How Food Works

198 199DIETS

High-fiber diet

How does it work? Stomach STOM
Soluble fiber encourages the body to
Fiber helps with weight loss in a range use and expel cholesterol, reducing the
of ways. It isn’t easily digested, so it risk of developing heart disease. It forms
doesn’t provide many calories, but the a gel when mixed with liquid in the
bulk makes you feel full quickly. High- stomach. This helps slow the release
fiber foods also need a lot of chewing, so of sugar into the bloodstream, avoiding
you eat more slowly, meaning your body the sugar rush that is common after
eating low-fiber carbohydrates.

can register you are full before you overeat. Food is churned
Fiber-rich foods also travel slowly through in stomach for
the stomach, keeping you full for longer, several hours
so it is easier to resist unhealthy snacks.
Soluble fiber (see p.24) can even reduce NTESTINE
blood sugar spikes after meals, which helps
ACHSMALL I
to avoid insulin resistance (see pp.216–17). Soluble fiber slows
NER sugar absorption in

small intestine

Large molecule of Gases FOOD IN STOMACH
fiber being broken produced by
Broccoli provides down by bacterial fermentation
vitamins as well as fiber
fermentation

DIN TINE
LARGE INTES LARGE INTESTINE

FIVE BEAN CHILI WITH FOLDED WALL OF INTESTINE Bacteria lining wall
BULGAR WHEAT AND of intestine

BROCCOLI Short-chain
fatty acid
produced
by bacteria

Keeping regular BLOODSTREAM

Fiber helps keep your gut healthy by Products of fermentation, including
bulking out and softening your stool vitamins K and B, enter bloodstream
and reducing the time it takes to pass Colon
through the bowel. This can help reduce Fiber passes through the stomach and small
constipation. Fiber is also prebiotic, intestine relatively unchanged, but in the colon,
meaning it feeds beneficial gut bacteria. some types are fermented by bacteria. Although
These bacteria produce byproducts that this produces embarrassing gas, it also generates
help keep our colon cells healthy and beneficial products including some vitamins and
protect against bacteria that can make short-chain fatty acids. Over time, the gut adapts
us ill by making the colon more acidic. to a higher-fiber diet and flatulence decreases.
The bacteria also produce vitamins B
and K, which we can then absorb.

Intermittent fasting

Fasting has traditionally been part of many religious SHOULD YOU
diets, but recently it has started to gain more interest in EXERCISE ON FAST DAYS?
scientific communities. In addition to helping with
weight loss, it is thought that intermittent fasting There is evidence to suggest
has the potential to produce other health benefits. that exercising while fasting
helps the body burn more fat.
Common fasting diets
However, it makes sense
Intermittent fasting diets involve sequenced periods of fasting and non- to limit yourself to moderate
fasting. In the 5:2 diet, dieters eat normally on five days a week (feast days)
but have a much reduced calorie intake on two nonconsecutive days (fast forms of exercise on
days). The alternate day diet involves eating whatever you like one day, then fast days.
fasting the next. Diets that involve a restricted feeding window allow you
to eat only during a set time period each day—usually of 8–12 hours.

DAY 1 DAY 2 DAY 3 DAY 4 DAY 5

5 : 2 DIET

FAST FAST

ALTERNATE DAY DIET

FAST FAST

EIGHT-HOUR DIET Fasting menu BREAKFAST LUNCH SUPPER
On fasting days,
0 No food calorie intake is Miso Small
consumed restricted to about soup turkey
20 one-quarter of the burger
recommended daily
18 6 Food eaten in intake. On the right 1 egg 5 asparagus 1 crispbread corn on the cob
an eight-hour is an example of a 90 KCAL 60 KCAL 330 KCAL
window daily meal schedule
of 490 calories.

12

200 201DIET

Intermittent fasting

Is it good for you? BENEFITS DRAWBACKS

The evidence that suggests that Simple rules and easy to follow Possibility of extreme hunger, headaches, and
intermittent fasting is good for tiredness on fast days
weight loss comes mainly from
animal studies (see below). If these No special food or supplements are required Risk of mood swings and irritability
results are applicable to humans,
these fasting diets could be Possible health benefits Long-term effects not yet understood
effective in countering obesity—
and the health benefits of that are Offers some flexibility—you don’t need to fast Risk of low blood pressure on fast days may
widely known. However, the very
few human studies on fasting have on the same days each week make driving dangerous
had mixed results and we don’t yet
understand the potential negative Some people report increased energy May not suit some people’s lifestyles
impacts of fasting.
Reduced food costs Can be hard to keep it up over a long period

On fast days, frees up time usually spent Some people believe that fasting can lead to
planning meals an unhealthy obsession with food

DAY 6 DAY 7 Potential health benefits

There is growing evidence to support the health benefits of fasting in
animals. Positive effects on blood pressure, insulin sensitivity, and the
risk of some chronic diseases have led some scientists to believe that
fasting has the potential to produce similar health benefits in humans.

Increased insulin
sensitivity
RESULTS OF Higher insulin sensitivity
STUDIES ON ANIMALS helps the body to process

glucose in carbohydrates
more efficiently, reducing
Lower blood the risk of obesity and Fighting
pressure diabetes. cancers
When used both on
Fasting has been its own, and alongside
shown to reduce blood
pressure in mice, and even chemotherapy, fasting has
been shown to slow the
FAST maintain blood pressure Helps brain growth and spread of
Feast and famine levels when they were diseases some cancers
Of the variety of fasting regimes available, fed a high-calorie in mice.
the three pictured here are among the diet. Fasting has been shown
most popular. Fasting involves considerable to slow cognitive decline
commitment, and may not suit some in mice with engineered
lifestyles, but the degree to which people versions of Alzheimer’s
fast varies. Some follow a 500kcal fasting Reduced and Parkinson’s Improved
regime (see left), but others commit to cancer risk disease. brain health
300kcal a day, or even nothing but water. Fasting mice have been Increased cell Feeding mice a
found to experience resistance restricted-calorie diet
significant reductions in has improved brain
cell proliferation, The heart and brain neuron regeneration
considered an indicator cells in fasting mice have and improved the
for cancer risk. cognitive abilities
of older mice.

become more resistant to
the damage caused by
heart attack and
stroke.

Detoxing CAN NATURAL
PRODUCTS EVER DETOX?
A recent fad has seen ranges of items, including Although there is very limited
drinks, supplements, and even shampoos, being evidence from animal studies
sold as “detox” agents that we can use to cleanse that cilantro may help to expel
our bodies and eliminate toxins. However, there heavy metals, heavy metal
is no scientific evidence to back up such claims.
poisoning is a serious
The detox claim problem that requires

Detox proponents claim that by following a particular diet, or using medical treatment.
certain products, we can help our body to flush-out toxins that have
built up through our exposure to substances such as alcohol, caffeine, GOJI BERRY
tobacco, fat, and sugar. Detoxing can therefore improve our health.

Detox methods
A whole industry has built up around an array of
detox methods and products. These include diet
regimes, fasting, food supplements, and even
invasive procedures such as colonic irrigation.

ACAI BERRY SUPPLEMENTS LAXATIVES FRUIT
CELERYHERBAL TEA
TOXINS BUILD DETOX
ED
BEETS-UP

GARLIC JUICE

SMOOTHIES

202 203DIETS

Detoxing

What are toxins?

Many substances can be harmful in large doses—even water. However,
the body has an efficient system in place, featuring the liver and kidneys,
which neutralizes or expels excess harmful chemicals daily. Toxins do
not accumulate as detox advocates claim. There are a few exceptions,
however. Some dangerous chemicals that dissolve in fat can build up
in our fat stores over years. Exposure to these should be limited.

POPS Iodine Toxic A NORMAL,
Persistent An essential metals HEALTHY
organic pollutants nutrient, iodine can Fish may contain PERSON HAS
can come from paint be toxic in high doses, heavy metals including NO NEED TO
and ink, and residues particularly for people mercury. It accumulates DETOX
of pesticides with defective in the food chain, so
on food. predatory fish may
kidneys. have high levels.

The reality of detoxing PRODUCT CLAIM REALITY
Herbal teas
Our bodies have sophisticated Supplements Herbal teas help to flush toxins They can have a diuretic effect,
ways of removing most of the Superfoods out of your system making you urinate more—giving
unwanted substances we ingest. Detox patches the appearance of “flushing”
Therefore, it is doubtful that the Calorie
term “detoxing” has any real restriction Supplements boost your body’s While valuable in some cases of
validity. The mainstream medical Laxatives detoxing organs with scientifically deficiency, there is no evidence
view is that the idea is little more developed vitamin formulas for their detoxing properties
than a marketing myth and a waste
of time and money. Some foods, such as garlic, help They may contain high amounts
to decrease the buildup of of vitamins and minerals that are
COLONIC IRRIGATION toxins in the body essential to our general health

Colonic irrigation is a potentially Detox patches draw toxins out There is no evidence supporting
dangerous practice of inserting through the skin the idea that toxins can be drawn
liquids (often herbal concoctions out through the skin
or even coffee) through the rectum
into the colon, and holding it there Fasting or low-calorie diets will Denying your body the nutrients
before expelling it. Despite what help you detox and lose weight it needs to function can result in
its advocates claim, the colon does serious health problems
not need cleaning, and this practice
can perforate its lining, leading Laxatives can help to cleanse Regular use can lead to
to serious complications. your colon dependency—you may struggle
People have even died from to pass waste without them
infections caused by colonic
irrigation.

Popular diets

With a 2014 WHO report finding 39 percent of adults worldwide overweight
or obese, dieting has never been more popular or necessary. But with so
many diets available, which are scientifically proven to be healthy and
effective? For some, the consensus is clear, but for others, the jury is still out.

Lifestyle choices Diet What are its goals? How is it supposed to work?
Low-calorie
The word “diet” is often used to Low-fat The basic equation for weight loss is to consume fewer calories
talk about short-term changes or Very low- than you use—counting calories can help ensure this happens.
significant adjustments in eating calorie
habits for a set time frame. Low-carb Fat is high in calories, so reducing the amount eaten cuts total
Weight loss can often be achieved Low-GI calories consumed and encourages weight loss. In the past, it was
in these ways, but the results are (glycemic also thought to help cut cholesterol and heart disease risk.
unlikely to stick if a long-term index)
change in lifestyle is not made. High-fiber By drastically reducing calorie intake, a very low-calorie diet
Indeed, if the dieter simply returns Mediterranean is designed to promote rapid, short-term weight loss.
to earlier habits, any weight lost Paleolithic
will almost certainly be regained. Intermittent Low-carb diets claim carbohydrates are stored more easily as fat.
For sustained weight loss and fasting Some reduce carbohydrates enough that the body starts burning
maintenance, healthy choices need Clean eating fat reserves as it enters ketosis, leading to weight loss.
to turn into lifelong behaviors. Alkaline
Macrobiotic The glycemic index measures how rapidly food raises blood sugar
BY 2025 GLOBAL Blood-type levels. Low-GI foods help you feel fuller longer, keeping your body
OBESITY LEVELS MAY from producing so much insulin (which promotes fat storage).
REACH 18 PERCENT
Fiber fills you up and keeps you full for a long time, reducing the
IN MEN AND amount you feel you need to eat. Much of it isn’t digested, so it
21 PERCENT doesn’t provide many calories.
IN WOMEN
Mediterranean people live long and healthy lives. Many have tried
DO CRASH imitating their diets in the hope of reaping the same benefits.
DIETS WORK?
Proponents claim that we haven’t evolved since Paleolithic (Old
While following a very low- Stone Age) times, so we can’t process food produced by farming.
calorie diet can lead to rapid By replicating our ancestors’ diets, they claim we will be healthier.
weight loss, it is essentially
impossible to lose more than By restricting calorie intake to particular times of day, or days of
the week, this approach is designed to lower the overall calorie
about 3lb (1.5kg) of fat in intake and encourage fat burning and weight loss.
one week, even if you
could eat nothing. Based on a “whole food” approach, clean eating advises avoiding
anything “processed” in order to eat a higher quality diet, feel fuller
for longer, and be more mindful of the food being consumed.

Claims that some foods have an acid-producing effect, and the
body has to work hard to bring its pH under control. Eating alkali-
producing foods aims to ease this pressure and improve health.

This diet focuses on consuming a balance of foods that are locally
produced, in keeping with the seasons. Rather than strict
guidelines, the food eaten varies from person to person.

Advocates of this diet argue that our different blood types affect
how we digest food. To optimize health, they say we should eat the
right foods for our blood type.

204 205DIETS

Popular diets

Crash and burn C ABBAGE SOUP

A persistently popular fad diet is the cabbage soup diet. Based on
eating a low-calorie soup (and little else) for one week, many experts
criticize it as a quick fix, with much of the weight lost being water,
not fat. This is because reducing calorie intake leads the body to burn
through glycogen stores for energy. Glycogen retains water, so using
it also releases the “water weight,” but this can be quickly regained.

What does it consist of? What do people eat or avoid? Is there evidence that it works?

No foods are off limits, but portions are controlled and Yes—reducing your calorie intake is a surefire way to lose weight, but it
low-energy-density foods are preferred. can be hard to stick to because you need to track everything you eat.

Dieters switch to low-fat versions of products such as cheese and Low-fat products are often high in sugar and may not keep you full. While
yogurt, and eat lean cuts of meat. The consumption of high-fat foods, it is a way to cut calories, some fats (such as the unsaturated ones in olive
such as oils and spreads, is limited. oil and oily fish) are necessary for health.

Some or all meals are replaced with “nutritionally balanced,” Can lead to rapid weight loss at first, but products lack many of the
low-calorie, ready-made drinks, soups, or bars. Any other food eaten benefits of normal food. Cannot be followed long-term, and doesn’t
should be healthy and low in fat. Products can be very expensive. change eating habits, so weight often returns when the dieting stops.

Bread, pasta, grains, and starchy vegetables are off limits. In some Limiting refined carbohydrates is sensible as they are energy-dense and
extreme cases, a lot of fruit and vegetables are banned at the start easy to overeat, but cutting out fruit and vegetables is never wise. Can
of the diet. Protein and fat are unlimited. help short-term weight loss, but longer-term consequences are not clear.

Whole-grain products are promoted, because they have a generally Low-GI isn’t always healthy—fries, for example, are lower-GI than boiled
lower GI than their white counterparts. Only carbohydrates have a GI potatoes. But this diet may be beneficial in preventing and treating
rating, so fats and protein are not limited. obesity and related diseases, such as type 2 diabetes.

Whole-grain cereals, fruit and vegetables (especially with skins) are High-fiber diets can help with weight loss, and have lots of other health
good sources of fiber. Processed foods generally aren’t, and fats and benefits, such as reducing the risk of certain cancers, decreasing
protein don’t contain fiber. cholesterol levels, and promoting good gut bacteria.

Traditional Mediterranean diets focus on fresh vegetables, whole grains, There is some evidence olive oil is protective against a range of
olive oil, garlic, and some fish, fruit, and wine. Sugar, red meat, and age-related diseases. The plant-based, high-fiber approach of
processed foods are limited. the diet also makes it a good choice.

Most grains and dairy are out, but plenty of meat, leafy greens and nuts Eating less processed food and more vegetables is good, but there is no
are consumed. Processed food, salt, and sugar are also avoided. evidence that most of us have trouble processing cereals. Our ancestors
did not have one specific diet, and we have adapted to more variety.
Followers eat normally part of the time and restrict calories
dramatically on certain days or at certain times. On fast days, only 500 There is emerging evidence that fasting can benefit health. Many people
calories are allowed by some regimes, which is very limiting. lose weight on this diet, as the lack of restriction on non-fast days fits in
with a busy lifestyle.
There is a focus on expensive “superfoods,” such as chia seeds, goji
berries, and organic kale. Normal sugar is out, but honey, maple syrup, Some principles are sound (more fruit and vegetables, fewer refined
and coconut sugar are fine, as are foods processed at home. carbohydrates, sugar, and salt) but some advice is illogical—the sugar
in honey is just as bad for you as refined sugar.
Lemon water is recommended to make your body more alkaline. Fruit
and vegetables are encouraged; meat, dairy, and most grains are out. The pH of the blood is tightly controlled. Acidic blood would indicate a
serious illness, and drinking lemon water will not help. However, the focus
Whole grains, vegetables, and beans are encouraged. Dairy, eggs, meat, on fresh fruit and vegetables in this diet is good.
tropical fruits, and nightshade vegetables (including tomatoes and
eggplants) are to be avoided. Good for reducing food miles and meat consumption, but devotees miss
out on some healthy foods. Its focus on vegetables and whole grains, with
Based on ideas of when blood groups evolved and what was eaten by limited fat and sugar, might help you lose weight.
ancestors at those times. Type O should eat a “paleo”-style diet high in
meat, while A should be vegetarian. B can consume more dairy. There is no evidence that blood type affects the way we process food or
that this diet improves health. The theories of when each blood group
evolved have been disproven by genetic evidence.

Allergies FIRST EXPOSURE

Protein in

peanut ingested

An allergy is the body’s oversensitive immune

response to a substance that should normally be STOMACH
harmless. Food allergies cause a variety of symptoms,
ranging from the uncomfortable to the life-threatening. TESTINE

How allergies work Amino acid IN
absorbed
In people with food allergies, exposure to specific proteins in into body
particular kinds of food causes their body’s immune system to
react inappropriately. It triggers the release of chemicals into the 1 Protein absorbed
bloodstream that aggravate or inflame different parts of the body. The trigger food—in this case
Food allergies may cause skin problems, such as itching and peanuts—is ingested and the proteins in
eczema, and digestion issues including nausea and diarrhea. it are broken down into amino acids, which
Severe allergies may also cause asthmatic symptoms, or even are absorbed through the gut. Exposure can
a systemic reaction—anaphylaxis—that can be fatal. also be through skin contact or inhalation.

1–2 PERCENT OF ADULTS AND IMMUNE
8 PERCENT OF CHILDREN IN CELL
THE UK HAVE A FOOD ALLERGY

PEANUTS NO SYMPTOMS Antibody released
by immune cell

2 Antibodies produced
If allergic to peanuts, the body’s
immune cells produce antibodies that are
specific to the particular allergen. The
antibodies travel in the bloodstream.

ALLERGIES ON THE RISE Antibody bound
to mast cell
Food allergies are on the rise in developed countries,
but scientists aren’t sure why. One popular idea, known MAST CELL
as the “hygiene hypothesis,” suggests that the fact our
children don’t encounter as many pathogens, BACTERIA 3 Mast cells
such as bacteria, as they used to has somehow The antibodies bind to the surface of
affected the natural development of their white blood cells called mast cells, which
immune systems. Another theory is that become sensitized. At this stage there are
modern lifestyles—including diet, antibiotics,
and hygiene—interfere with our gut flora.
We know these microbes moderate our
immune systems, so this interference
may affect how our immune cells are
primed, causing allergies.

no symptoms of an allergy, but the cells are
primed for a second exposure.

SUBSEQUENT EXPOSURE 206 207DIETS

How allergies are diagnosed Allergies
Skin prick test
A combination of a detailed patient history A medic pierces the patient’s skin with
and either a skin prick test or blood test tiny amounts of suspected allergens,
for food-specific antibodies are used to producing localized allergic responses
diagnose food allergies. Food exclusion, in the form of bumps and redness.
and blind and placebo-controlled oral food
SWOLLEN tests are also effective, but must be done
LIPS under careful supervision.

T SWOLLEN THROA Treatment options AUTOINJECTOR
Emergency treatment
The main treatment for allergies is to avoid People with severe allergies may need
the trigger food, but this isn’t always easy. to carry with them two autoinjectors (a
In severe cases, even tiny amounts of the spring-loaded syringe) of adrenaline for
allergen can cause reactions. Medicines are emergency treatment. Adrenaline narrows
used to prevent and alleviate the symptoms blood vessels, relieves blood pressure, and
reduces swelling.
of allergic reactions. For mild allergies, such
as hayfever, antihistamines can help by S
blocking receptors from binding PEANUTS
to histamine chemicals.

MAST
CELL

Protein bound SYMPTOMS OCCUR
to antibody

4 Proteins bind to antibodies SWOLLEN HAND
On subsequent exposure, mast cells
identify the protein allergen, which then
binds to the antibodies on the mast cells.
This activates a process called degranulation.

ONLY IN EXTREME CASES

MAST CELL Chemicals such Body-wide allergic
as histamine reaction
released

ABDOMINA Chemicals 6 Anaphylaxis
released over In severe cases,
known as anaphylaxis, the
entire body

L PAIN whole body is affected over
a very short period, resulting
in a combination of extreme
5 Mast cell releases chemicals symptoms that can include
As the mast cell degranulates it throat swelling, severe
releases histamine and other chemicals
into the bloodstream. It is the effect of asthma, and a drop in
blood pressure. Emergency
these chemicals on the body that treatment is necessary.
produces different allergic symptoms.

Intolerances

Intolerances occur when the body is unable to digest Lactose intolerance
a component of food. They differ from allergies in that This type of intolerance is one of the most
they do not aggravate the immune system. People can common. It occurs due to a lack of the
be intolerant to a range of foods—and either be born enzyme lactase, which breaks down lactose
intolerant, or become sensitive later in life. sugar. Without this enzyme, the sugar is
fermented by bacteria in the colon.

What causes intolerances? Galactose
Glucose
Intolerance can occur when you don’t have a particular digestive enzyme
that helps break down nutrients. Sometimes, it is a part of the food that
can cause intolerances, such as artificial additives, natural chemicals,
or toxins. Symptoms often arise hours after eating and may continue for
days. They vary from case to case, but commonly include nausea, bloating,
cramps, and diarrhea. Rarely, temporary intolerances can arise after bouts
of gastroenteritis or courses of antibiotics.

Diagnosis

Intolerances are difficult to diagnose as symptoms are delayed
and more than one intolerance can coexist. Exclusion diets instruct a
patient to cut a potentially problematic food out of their diet for a few
weeks to see if symptoms improve. If symptoms recur once the food
is reintroduced, an intolerance is diagnosed.

FOOD Exclusion period Reintroduction period

SYMPTOMS

TOLERANCE YOGURT
Time Live cultures
Research has shown that yogurts
Creating tolerance with live cultures (bacteria) can help
Extended elimination (weeks to months) of the offending relieve the symptoms of lactose
food can, in some cases, lead to a rise in tolerance. intolerance, because the bacteria
Reintroducing the food in small doses may be tolerated break down the lactose for you.
and symptoms may lessen with time.

PEOPLE INTOLERANT TO
AVOCADOS ARE SENSITIVE
TO A SUBSTANCE IN THEM
CALLED TYRAMINE

208 209DIETS

Intolerances

SMALL INTESTINE Lactase enzyme WHAT IS CANDIDA?

Lactose sugar Candida is a group of yeasts
that live naturally in the body,
1 Lactose in most commonly in the mouth
small intestine and vagina. The yeasts may
When the cells that line the walls of also live in the gut, as part of
the small intestine encounter the the normal gut flora. It is often
Lactose digested sugar lactose, they start to produce thought that overgrowth of
2 by lactase the digestive enzyme lactase. Candida in the gut can cause
irritable bowel syndrome, but
Lactase breaks lactose into research suggests that it may
two smaller sugars— be the reverse – bouts of IBS
galactose and glucose. can upset the balance in your
gut and cause Candida to
3 Galactose and glucose absorbed WHY CAN LACTOSE thrive. This may lead to
These two smaller sugars are then INTOLERANCE DEVELOP symptoms akin to having IBS
absorbed into the bloodstream by the or even a persistent food
small intestine. LATER IN LIFE? intolerance: nausea, gas,
diarrhea—leading to Candida
1 Undigested lactose Lactase production decreases being falsely blamed as the
Those who are lactose at varying rates with age, so “cause” of these afflictions.
intolerant will not have the your ability to digest dairy
lactase enzyme, so lactose CANDIDA YEAST
cannot be absorbed and instead products may reduce as
passes into the large intestine. you get older.

Bacteria ferment 2 Bacterial fermentation
lactose Lactose is fermented by

bacteria living in the large intestine, 3 Disruption in the bowel
Acids draw water into the
producing gas and acids in the process. bowel, causing diarrhea, while the

gas produced by fermentation
causes bloating and discomfort.

Gas and acids
released by
bacteria

LARGE INTESTINE

Undigested
lactose enters
the large
intestine

Exclusion diets TREE NUTS

For people who suffer from a food allergy

or intolerance, often the only treatment Tree nuts EGGS
is to avoid the trigger food. Unfortunately, include cashews, brazil
if they aren’t careful, this can lead to nuts, hazelnuts, walnuts, Egg is one of
deficiencies in certain nutrients. and almonds, but not the most common
peanuts, which are legumes. food allergens, particularly
Allergies and intolerances People with tree nut allergies in young children. Fortunately,
are usually sensitive to most children grow out of egg
allergy by the time they reach
most tree nuts.
double digits.
The body’s adverse immune response to proteins in certain

foods can lead to a variety of allergic symptoms, from MUSTARD
itching and rash, to nausea and anaphylactic shock. Food
allergies affect more than 1 in 20 children but are less

common in adults. In cases of food intolerance, symptoms Although very
rare, mustard allergy
arise from deficiency of certain digestive enzymes (as is is thought to be more
the case with lactose intolerance), or the direct common in countries where

action of chemicals within foods. LUPIN mustard—including mustard
seeds—plays a large part in the
FOOD ALLERGIES Lupin is a
VARY REGIONALLY. legume in the same diet, such as France.

IN ASIA, RICE family as peanuts, and like
peanuts, its allergens can
trigger anaphylaxis. Lupin flour
ALLERGY IS ONE OF and seeds are sometimes used MOLLUSKS
in baking and pasta.
THE MOST COMMON
Mollusks
Trigger foods include scallops,
Any preprepared food or drink sold in Europe must mussels, clams, oysters,
clearly state on the label if it contains any of the ingredients octopus, and squid. They
shown here (right). However, in other parts of the world, have only quite recently been
different trigger foods are more common. added to the EU list for
mandatory labeling of
DAIRY NUTRIENTS ALTERNATIVE SOURCES
allergens.

Calcium Leafy green vegetables, MILK SOYBEANS
Zinc fortified milk alternatives
Vitamin B2 Red meat, whole grains Milk from cows Soybeans are
Vitamin D Beef liver, lamb, almonds (or other animals) is widely used in
Sunlight, oily fish, fortified milk one of the most common processed foods and in
alternatives, fortified cereals allergic triggers, particularly Asian sauces. Allergy to
in children. It is distinct from soybeans is quite common,
lactose intolerance, which is especially in young children,
but symptoms are
nonallergic. typically mild.

Dairy-free diet
Cutting out dairy means losing out on a valuable source of nutirents,
but it is fairly easy to swap cow’s milk products for alternatives made
with soy, rice, and nut milks. There are plenty of alternatives to
replace the calcium, zinc, and vitamins in dairy foods.

210 211DIET

Exclusion diets

GLUTEN NUTRIENTS IN ALTERNATIVE SOURCES
GLUTEN-RICH FOODS Beans, fruit, vegetables, nuts
Intolerance to
gluten, found in Fiber
wheat, rye, and barley, is
PEANUTS spreading around the world, B vitamins Non-gluten-containing
probably due to the whole grains such as brown
One of the Westernization of diets, and rice and quinoa
most common food the replacement of rice with
allergies, peanut allergy wheat products. Vitamin D Sunlight, oily fish, fortified
has been on the rise in milk products
children in the last few years.
Exposure to even trace amounts Folic acid Leafy green vegetables, beans
can cause potentially fatal
Iron Meat, leafy green vegetables
anaphylaxis.

FISH Calcium Dairy foods

Fish Zinc Red meat, dairy foods
including tuna,
salmon, and halibut, Magnesium Leafy green vegetables, nuts,
can cause severe allergic and seeds
reactions in some people.
These should not be confused CRUSTACEANS Gluten-free diets
with our reaction to histamine A wide range of gluten-free foods is available,
released by Vibrio bacteria— Thought to but a diet free of gluten can be short of nutrients.
that is food poisoning. result in the greatest There are many natural and unprocessed foods
number of severe allergic that can help you to remedy any deficiencies in
SESAME SEEDS reactions, the allergy to crabs, fiber, vitamins, and minerals.
lobsters, and shrimp, usually
Sesame seeds appears during adulthood.
are also eaten in the
form of flour, oil, and Diet dangers
paste. Although relatively
uncommon, sesame allergy There is a risk that exclusion diets
is more common in people
allergic to other foods. can lead to malnutrition, particularly in

children. If a child doesn’t receive the right

balance of proteins, carbohydrates, and fats,

as well as essential vitamins and minerals, their

growth and development may be affected, and they

SULFITES are at risk of various illnesses. It is important that
the parents of children with allergies understand

Sulfites are CELERY how to replace any nutrients missing from
used as preservatives their child’s diet.
in products such as pickled Exposure to
and dried foods and alcoholic celeriac and celery can Stunted growth
drinks. Although uncommon, trigger severe symptoms, Children with multiple food
intolerance can produce including anaphylactic shock. allergies have been shown to
asthmalike symptoms. It is most common in be shorter, on average, than
others their age, suggesting
European countries. diet-related growth problems. NORMAL STUNTED

Rickets
Cases of children developing
rickets (osteomalacia) through
inadequate calcium and deformed leg bones

vitamin D intake because of
milk allergy have been seen. AFFECTED CHILD

Diet and blood pressure

Along with other lifestyle choices, what we eat and drink can
have a direct effect on our blood pressure. High blood pressure—
also known as hypertension—is a long-term medical condition
that can lead to cardiovascular disease. However, this “silent
killer” is both preventable and treatable.

180+ Stages of hypertension
Blood pressure is reported
HIGH: STAGE 2 HYPERTENSION in millimeters of mercury
(mm Hg). As it rises above the
160 normal level, it reaches a stage
of prehypertension before
HIGH: STAGE 1 HYPERTENSION two stages of hypertension.
At stage 2, the risk of
140 developing cardiovascular
diseases is very high.
PREHYPERTENSION

SYSTOLIC BLOOD PRESSURE (MM HG) 120

NORMAL

Blood pressure readings

Measuring blood pressure as the heart beats
gives systolic (beating) and diastolic (rest)
values. An average healthy blood pressure
reading is below 120/80. A person has
hypertension if their reading is higher than
this over a sustained period. Factors that
cause blood pressure to rise include eating
too much salt, being obese, drinking too much
alcohol, and smoking. It can be countered
through dietary and lifestyle changes.

90

LOW

40 60 80 90 100 120
40
DIASTOLIC BLOOD PRESSURE (MM HG)

212 213DIETS

Diet and blood pressure

Why is high blood pressure dangerous?

Although there are rarely any symptoms of high blood WHAT IF I
pressure, if it is left untreated the heart gradually CAN’T GIVE UP SALT?
becomes enlarged and less efficient. Slowly, the blood

vessels, kidneys, eyes, and other parts of the body can Alternatives to regular salt are
become damaged. As blood pressure goes up, artery available. These usually contain
walls become thicker and stronger and arteries potassium rather than sodium.
become narrower, threatening to slow or even stop However, too much potassium
blood flow. This increases the risk of heart attack,

heart failure, and stroke. can be dangerous for people

Thick, tense with kidney problems.
muscle during
systole (heart Blood cell Thinner, relaxed muscle Much-thickened Restricted
pumping) during diastole (heart muscle tenses blood flow
at rest) during systole

BLOOD IN ARTERY

NORMAL BLOOD PRESSURE CHRONIC HIGH BLOOD PRESSURE

Healthy arteries Narrowing arteries
A normal blood pressure changes from a high, as the heart If your blood pressure is high, your arteries have to work harder
pumps, to a low, when it relaxes. The muscles in our artery walls to resist the pressure, so their walls become stronger and thicker.
respond to these fluctuations by tensing and relaxing in rhythm. As your arteries get narrower, blood pressure rises further.

Dietary solutions NUTS, SEEDS, SWEETS WHOLE
LEGUMES <1 6–8
The best ways to reduce blood pressure are to
reduce your salt intake and maintain a healthy LPEO<AU2NLTMREY,AFT,ISH <1 GRAIN
weight. Sodium is the dangerous ingredient in salt,
and switching to salt with low sodium can help. FATS, OILS LOW-FAT
More broadly, the DASH (Dietary Approaches to 2–3 2–3
Stop Hypertension) diet is an initiative in the US that
focuses on eating more fruit, vegetables, and whole DAIRY
grains, as well as reducing salt, saturated fats, and
alcohol. Although it wasn’t designed for weight loss,
it can easily be adapted by reducing portion sizes. The
DASH diet has been shown to lower blood pressure,
reduce cholesterol, and improve insulin sensitivity.

WORLDWIDE, THE FRU4IT–6 VEG4–E5TABLES
NUMBER OF PEOPLE Food group portions
WITH UNCONTROLLED The DASH diet offers a guide to how many portions of each food
HYPERTENSION group to eat each day. For nuts, seeds, and legumes, the advised
EXCEEDS 1 BILLION dose is 4–5 portions a week; for sweets, 5 portions or fewer a week.

HIGH LDL-, HIGH HDL-CHOLESTEROL Meat Saturated fats
Nuts These fats tend to increase
KEY Milk levels of both bad and good
cholesterol in blood. Until
LDL (bad) recently, experts thought that
cholesterol the good cholesterol could
compensate for the bad
HDL (good) cholesterol, but now it is
cholesterol thought this isn’t true. Some
types of saturated fats are
HIGH LDL-, LOW HDL-CHOLESTEROL harmful in certain people so it
is worth limiting intake to less
than 7–10 percent of total
energy intake.

Trans fats
Trans fats, which are created by
hydrogenating vegetable oils, raise
bad cholesterol levels and lower good
LOW LDL-, H Cookies cholesterol levels. People eat them in

cakes, cookies, margarine, and
deep-fried foods. They are so bad for
you that some authorities can find no
IGH HDL-CHOLESTEROL safe amount of trans fats to recommend
Cake in the diet, and some countries have

gone as far as banning them altogether.

Chips

Unsaturated fats Fats and cholesterol
Eating unsaturated fats
can lower the level of bad Although fat is an important part of our
cholesterol and raise levels diet, some fats are healthier than others.
Olive oil of good cholesterol. This Eating different types of fats affects
the levels of the different types of
leads to a range of benefits cholesterol in our blood (see pp.30–31),
such as lower blood pressure with negative and positive effects. While
and a lower risk of heart “bad” cholesterol contributes to the build
disease. Olive oil is a good up of fatty deposits on our artery walls,
Avocado source of monounsaturated “good” cholesterol transports cholesterol
to the liver for removal.
fat, and its beneficial effects
on cholesterol levels may
be key to the healthiness
Salmon of the Mediterranean diet.

Heart disease IS HEART DISEASE
and stroke REVERSIBLE?

Diet plays a major role in the development of heart By making radical diet and
disease—the leading cause of death in the developed lifestyle changes some people
world. By eating less of some types of foods and more have been known to halt the
of others, we can combat the key conditions that lead development of heart disease
to heart disease and stroke, including high cholesterol
levels, high blood pressure, and obesity. and achieve improved
blood flow to
the heart.

214 215DIETS

Heart disease and stroke

Cholesterol and heart disease 610,000

In people with a diet low in antioxidants (found THE NUMBER OF
in fruit and vegetables), too much cholesterol may AMERICANS WHO
lead to a buildup of fatty deposits (atheroma) on DIE EACH YEAR
the walls of the arteries. The body reacts with an FROM HEART DISEASE
inflammatory response that swells and thickens
the artery walls. This restricts blood flow, and OD VESSEL Blood cell
tissues beyond that point are starved of oxygen.
If this happens in the coronary LDL (bad) cholesterol carries
arteries it can lead to the fat to the artery wall
death of heart tissue.
If enough dies, a
heart attack or
heart failure
can result.
HEART
BLO Thickening
artery wall

Heart tissue Buildup of
starved of fatty deposit
oxygen dies (atheroma)
HDL (good)
FOOD FOR THE HEART AND BRAIN cholesterol
Narrowed artery
Certain foods can have a beneficial effect on the heart by Restricted blood flow
making the blood less viscous. Intake of omega-3 fatty acids Bad cholesterol carries fats to the
reduces the “stickiness” of blood, reducing the risk of clotting. artery wall allowing fatty deposits
Garlic is thought to have the same effect. Other foods are able to form, narrowing the artery. Fatty
to make blood vessels widen (dilate), allowing more blood to deposits may eventually rupture and
pass. Leafy greens, which encourage the production of nitric cause blood clots that can completely
oxide, are known to relax the blood vessels in this way. It may block blood vessels. When this type of
also be one mechanism by which moderate alcohol intake may obstruction occurs in arteries supplying
lower the risk of heart disease and stroke (see p.165). the brain, it results in a stroke.

GARLIC

LEAFY GREENS

Diabetes Pericardial
fat
Insulin is a hormone that helps muscle
and fat cells absorb glucose. Diabetes
occurs when the pancreas can’t produce
insulin or cells become insensitive to it.
If cells can’t absorb glucose, blood sugar
levels can become dangerously high.

Types 1 and 2 1 Visceral fat builds up
Visceral, or “deep,”
In type 1 diabetes, insulin-producing cells in the fat builds up around and HEART
pancreas are damaged and produce little or no insulin.
In type 2, the pancreas secretes insulin, but muscle within muscles and organs,
and fat cells do not respond to it by absorbing glucose, and lines the arteries over
and blood sugar levels become high. While type 1 years or decades. BLOOD
usually starts early in life, type 2 tends to develop VESSEL
later, and is linked to obesity. Type 2 diabetes, which
accounts for 90 percent of cases, is on the rise globally. Fatty liver LIVER

Vision Increased Long-term risks Visceral
problems and risk of stroke Over time, high blood adipose
sugar levels can harm
blindness Increased blood vessels supplying fat
risk of heart tissues all over the body.
disease This can result in damage INTESTINES
to the eyes and kidneys,
and can also increase
the risk of various
cardiovascular diseases.

Kidney failure Intra-
muscular fat

WHY DO
WOMEN GET DIABETES
DURING PREGNANCY?

The hormones that are

produced during pregnancy

can sometimes counteract the

effects of insulin, resulting

Foot ulcers in gestational diabetes.
and infections In most cases, it is only

temporary.

216 217DIETS

Diabetes

2 Glucose enters system 3 How insulin should work Prevention and
Glucose enters the The pancreas produces insulin management
bloodstream through the digestion when blood glucose levels rise.
of carbohydrates in food. This Insulin triggers receptors on muscle Losing weight is the single best
triggers cells in the pancreas to and fat cells, opening channels in the thing you can do to prevent and
secrete insulin into the blood. cell membrane and letting glucose in. control type 2 diabetes. There is
evidence that a Mediterranean diet
Insulin molecule Glucose flows in can help to stabilize blood sugar
opens muscle cell through open channel levels, and some research suggests
low-carbohydrate, low-GI, and
Glucose NG Buildup of fat causes high-protein diets can also help.
molecule NSULIN WORKI insulin resistance
INSULIN RE
SISTANT

4 How insulin DO DON’T
can fail
In muscle cells with Eat plenty of non- Eat too many processed
I a buildup of fat, the starchy fruit and foods that have hidden
vegetables daily carbs and calories
insulin receptors in
the cell membranes
become resistant and
block them. The Have an eating plan and Overeat, as this can

glucose channels become familiar with cause spikes in blood

do not open. the glycemic index sugar levels

Buildup of glucose not Drink plenty of water, Skip meals or eat at
absorbed by muscle cell which helps to dilute irregular times to avoid
the blood blood sugar dips

5 Insulin overload Watch out for hidden Drink much alcohol, as
As levels of glucose continue carbohydrates, this can keep blood
especially in fruit drinks sugar level elevated

Flood of insulin to rise, cells in the pancreas Choose healthy fat Eat too much salt, as
in blood increase their production of insulin, and low-sugar food high blood pressure is
resulting in insulin overload. alternatives common in diabetics
Insulin molecule

Obesity and insulin resistance COUNTING CARBS

Obesity is the single best predictor of type 2 diabetes. The global People with type 1 diabetes, and those
rates of each have risen to an almost epidemic state. Most people taking medication for type 2 diabetes,
who are obese not only have fat in the outwardly obvious fat stores, may choose to count the carbohydrate
but also hidden throughout their bodies. This fat increases the content of each meal or snack they eat,
resistance of muscle and fat cells to insulin, so that the cells fail so they know how much insulin to give
to respond and do not absorb glucose, no matter how high insulin themselves afterward.
levels become. Sugar then builds up in the blood—so much so that Overmedication can lead
it can make the blood thick, syrupy, and prone to infection. to a “hypo”—an episode of
low blood sugar that can
THE WORLD HEALTH be very dangerous.
ORGANIZATION PREDICTS THAT
DEATHS FROM DIABETES WILL
RISE BY MORE THAN 50 PERCENT
OVER THE NEXT DECADE

Cancer, osteoporosis, MOU TH
and anemia ESOPHAGUSBOWEL

What we choose to eat and drink directly affects our health

and, ultimately, our longevity. By consuming more of some

foods and drinks but restricting others, we can reduce the

risks of developing diseases and conditions including Foods that hurt or heal
cancer, osteoporosis, and anemia. By having a healthy, balanced
diet you can reasonably
Cancer Fish oils and expect to reduce your risk of
omega-3 fats developing cancer. However,
There is a seemingly constant turnover of Several studies have there is increasingly strong
foods and drinks that make the headlines produced evidence to scientific evidence that certain
for either causing or curing cancer. suggest that eating increased foods and drinks can cause,
However, interpretation of scientific amounts of oily fish, which are or help to prevent, specific
findings can be subjective, and claims for rich in omega-3 fatty acids, types of cancer.
“evidence” are often misleading. Cancer is decreases the risk of breast
a hugely diverse range of diseases, and the cancer in women.

causes and treatment of one type may be

very different from another. Nevertheless,

there are a few dietary choices we can

make that most experts believe will reduce LIVER
our risk of developing a range of cancers

and improve our general health. Fruit and
vegetables
EXPERTS BELIEVE THAT High fruit intake
1 IN 10 CANCER CASES lowers the risk of
COULD BE PREVENTED developing upper gastro-
BY HEALTHY DIETS intestinal tract cancer, while
both fruit and vegetables
reduce the risk of developing
bowel cancer.

SMALL
INTESTINE

WHERE DO THESE Fiber
FINDINGS COME FROM? Increased fiber
intake has been
Most of these findings come linked with a reduced
from the EPIC study, which has chance of developing
been following more than half cancers including those of
a million people across Europe the bowel and liver. Fiber helps
since the mid-1990s, looking to keep your bowels moving,
which may prevent the
at their diets and buildup of cancer-causing
health. compounds.

218 219DIETS

Cancer, osteoporosis, and anemia

Saturated fats Osteoporosis
There is some evidence to
suggest that increased saturated If bones do not take up or retain enough calcium,
fat intake leads to an increased they can become weak, with the increased risk of
risk of certain types of breast fractures—a condition called osteoporosis. Although
cancer in women. it is more common in older people, the process can
start much earlier. While hormone levels play a major
Alcohol role, a poor diet can be a contributing factor.
Even at moderate
levels, alcohol AMIN D CALCIU
increases the risk
of several kinds of VIT VIT M
cancer. These include FOL
Cancer cancers of the mouth, Eggs Fortified Dairy
cells larynx, esophagus, liver, Fish cereals Leafy
breast, and bowel. Bony greens
BREAST
fish
STOMACH
Foods for bone health
Osteoporosis can be prevented by eating a healthy diet
containing foods rich in vitamin D and calcium. These
include dairy products, fish, and leafy greens.

Salt Anemia
Salt intake
has been linked to Iron-deficiency anemia occurs when the body does not
stomach cancer. This could receive enough iron to produce enough red blood cells for
be because it damages the healthy circulation. A lack of vitamin B12 or B9 (folic acid)
stomach lining, or because it can cause macrocytic anemia—a rarer form in which red
makes it more sensitive to other blood cells are too large and don’t work properly.
cancer-causing chemicals.
IRON
Red and
processed AMIN B12 IC ACID
meat
Long blamed for Red meat Dark leafy greens
causing bowel and
stomach cancers, the role of Poultry Whole/fortified
red meat in cancer has been cereals
cast into doubt by new studies.
Nitrites in processed meat are Nuts and seeds
still regarded as a risk factor. Preventing anemia
You can prevent the onset of anemia by including
sufficient iron-rich food in your diet, as well as
foods rich in vitamin B12 and B9.

What to eat during Manganese
pregnancy A mineral found in many
different foods, manganese
Diet plays an important part in the Magnesium SPINEaids the formation of bone,BLOOD VESSEL
health of a woman and her baby Magnesium aids fetal SPINAL CORDcartilage, and connective
during pregnancy. Eating well will tissues in the growing fetus.
help the fetus to develop healthily bone and muscle
and ensure that its mother’s body development, and can PLACENTA
is in peak condition for the birth. help prevent the uterus BONES

Food to enjoy from contracting Iodine
prematurely. Iodine is important
Eating the right balance of different food for the growth and
types is essential for a healthy pregnancy. Folate development of the brain and
To keep energy levels high, mothers-to-be Folic acid (vitamin nervous system. Deficiency
can eat more unrefined starches, such as B9) is essential for the can cause cognitive
whole grains. Good sources of protein and development of an unborn and developmental
calcium, including lean meats and dairy baby. Deficiencies in the
products, are vital for supporting the baby’s mother can increase the problems.
growth and development. Eating at least five risk of her baby’s spinal
portions of fruit and vegetables a day helps cord failing to form
mothers get enough vitamins and minerals properly, leading to
to keep them and their growing babies in
optimum health. A balanced diet will also spina bifida.
help to ensure that weight gain during
pregnancy remains within healthy limits.

Good for mother and child Copper
Particular micronutrients present in different foods have Copper plays an
specific health benefits for a mother and her unborn baby. important role in the
In most cases these can be obtained naturally through formation of a baby’s
eating sufficient amounts of certain foods, but for some heart, blood vessels,
vitamins and minerals—as in the case of folate (folic acid, blood cells, and skeletal
or vitamin B9)—dietary supplements are recommended. and nervous systems.

KEY

Eggs Mushrooms Whole grains

Bread Rice Peanuts

Peas Cashews Milk

Broccoli Avocados Soybean

Bananas Cheese Fruit

220 221DIETS

What to eat during pregnancy

Calcium Foods to avoid
Calcium is an essential
mineral in the formation Some foods that can usually be eaten as part of a healthy diet
of bones and teeth, so pose a risk during pregnancy, either because they carry a higher
ensuring you have enough than average risk of food poisoning or because they contain
calcium in your diet is specific organisms or toxins that can be passed on from the
mother to the unborn baby and affect its development.
crucial during
pregnancy. Caffeine Liver
Iron Consumption of caffeine Liver, and some sausages and
Both the placenta should be limited as high patés, contain high levels of
and the growing fetus levels have been linked to low vitamin A, which can cause
place heavy demands on birth weight and miscarriage. birth defects.
the mother’s supply of
iron. Iron intake must Alcohol Fish
increase to supply the Alcohol is thought to be High levels of pollutants mean
placenta and to create unsafe for the developing that big predatory fish should
the fetus’s new baby, so expectant mothers be avoided and consumption
blood cells. should avoid it completely. of oily fish should be limited.

Soft and blue cheese Undercooked meat
Exposure to pathogens like Eating undercooked meat
listeria from unpasteurized can lead to bacterial or
dairy products can cause parasitic infections that can
miscarriage and stillbirth. seriously harm a fetus.

Game meat Multivitamins
Game meat that has been It’s best to avoid multivitamins
killed with lead shot should that contain high levels of
be avoided due to the health vitamin A, since this can be
risks posed by the lead. toxic to an unborn baby.

BRAIN GESTATIONAL DIABETES WHAT CAUSES
Choline FOOD CRAVINGS?
Brought on by hormonal changes
Only recently classified as an or simply the physical demands of Many women experience
essential nutrient, choline is pregnancy, gestational diabetes food cravings and aversions
key in the development of the occurs when the effects of insulin during pregnancy. These are
brain and spinal cord. Like are counteracted and blood-sugar thought to be caused by the
folate, it is thought to reduce levels become high. If left untreated, extreme hormonal changes
there are increased risks of the
the risk of neural defects. baby growing too large, that can affect a mother’s
premature birth, and taste and smell.
abnormal labor.
Treatment involves PREGNANT
tracking blood WOMEN ARE MUCH
sugar and making MORE LIKELY TO
dietary changes. CATCH INFECTIONS

Babies and children

During the first years of life, nutrition is critical for DIETS MUST BE BROAD
healthy development. Infants’ diets must provide the
right balance of protein, fat, and carbohydrate, along Babies raised vegan or on other
with vitamins and minerals including calcium and restricted diets must be carefully
vitamin D for bones and vitamin A for developing eyes. monitored to ensure they get all
the essential nutrients. Even getting
Babies Cup of water offered enough calories can be difficult
at meal times because vegan or vegetarian diets
For the first 6 months, babies get almost have lower energy densities than
everything they need from breast milk or Pureed food diets that include meat and fish.
formula, although breast-fed babies may need introduced Plenty of protein sources must be
extra vitamin D. After this, some of the milk included, along with adequate
should gradually be replaced with solid food. vitamin B12, iron, and vitamin D.
Puréed fruit and vegetables are good Supplements may be necessary.
starting points, followed by chicken
and other protein sources.

KEY First solids Breast milk or
Milk and dairy foods Babies often dislike a food the first formula still the
time they taste it, so it is good to major part of the diet
Other foods introduce new foods one at a time,
repeating each one even if they react Meat, fish, and
Mother produces dairy should
colostrum for a few negatively. Offering food that is now form part
days after giving birth, easy to hold helps babies learn of the diet

then breast milk to feed themselves.

6—9 MONTHS

Liquid diet Changing gut microbes
Breast milk has the right By the end of their first year, the
balance of nutrients for types of bacteria in the baby’s
newborns, helps boost their
immune system, and establishes gut begin to look more like
their gut bacteria (see p.25). those in an adult’s. Before this
Formula is usually made from time, they vary dramatically
cow’s milk, but has higher whey between infants, depending on
content and less casein protein the bacteria their environment
to make it more similar to
breast milk and easier to digest. has exposed them to.

BIRTH—6 MONTHS 9—12 MONTHS

222 223DIETS

Babies and children

Young children Fruit juice can Breakfast cereal DO CHILDREN
be given with is a good way to NEED SUPPLEMENTS?
As the proportion of calories a meal, once combine grains
from milk is reduced, a day and dairy in a meal
young children tend to be
encouraged to try lots of Babies and young children
different foods. But their diets often can’t get all the vitamins
should differ from adults’ in they need from milk and food.
some ways. Too much fiber,
for example, can fill small Vitamins A, C, and D are
stomachs quickly, preventing usually recommended for
children from eating enough children from 6 months
calories. Protein (including
dairy) is important. to 5 years.

Starchy food, such as Growing needs
butternut squash and A healthy diet for a 2–to-5-year-old should
grains should now be include three to four servings of starchy foods,
the same of fruit and veg, and two servings of
a part of meals protein. Skim milk or other dairy products (such
as yogurt and cheese) can replace the whole
milk. These are a good source of protein and

calcium, needed for growing bones.

2—5 YEARS

Diet continues to Grown-up foods
include protein, By 5 years, children’s diets
such as chicken
are, ideally, varied and
Milk alternatives Infant can start similar to an adult’s. Salt
From 1 year old, the baby’s intestines drinking whole
are able to digest the higher casein cow’s milk should not be added
content of whole cow’s milk. Fortified because of the potential
alternatives such as soy milk can be Low-fat (1 percent) harmful effect on kidneys.
used instead, but growth should be milk can be introduced Low-fat or skim milk is
now fine, since children
monitored because they contain to replace skim milk will get enough calories
fewer calories than whole cow’s milk.
from food.

5+ YEARS

1—2 YEARS PORTION SIZES

RICE MILK SHOULD NOT With childhood obesity rising,
BE GIVEN TO CHILDREN portion sizes are important. For
UNDER 5 AS THE ARSENIC a child under 3–4, a portion might
LEVELS ARE TOO HIGH be one slice of toast, 1/2oz (15g) of
oats, half an apple, or one egg, but
this depends on activity levels.

Eating disorders HOW LONG DO
EATING DISORDERS

Eating disorders are mental health conditions involving USUALLY LAST?

an unhealthy relationship with food and abnormal Research carried out in
eating habits. They have a devastating impact on the Australia suggests that the
day-to-day lives of millions of people and can cause average length of time that
a wide range of serious medical problems. someone suffers with anorexia
and bulimia is eight and

Three main types five years respectively.

People with anorexia believe themselves to be fat and starve

themselves to keep their weight as low as possible. Bulimia Anxiety, including feelings
involves some of the same attitudes as anorexia, but people of shame and guilt
alternate cycles of binge eating with purging—either
vomiting or taking laxatives. Binge eating is compulsively BRAIN

eating vast quantities of food, often without feeling hungry.

1 IN 100 FEMALES IN THE HEART Higher risk of heart
DEVELOPED WORLD WILL PANCREAS FAT TISSUE disease and heart
DEVELOP ANOREXIA attack
KIDNEY
Causes Increased levels of
body fat can lead
Eating disorders usually involve a degree of body to diabetes
dysmorphic disorder—a negative distortion of
how an individual sees themselves. There may Higher risk of
be a combination of factors that contribute to this. pancreatitis and
diabetes
LOW SELF-ESTEEM Chronic kidney BONES
People with low problems, or even Increased chance
self-esteem often of developing
have a negative body kidney failure osteoarthritis
image. As a result, they in the joints
may either find CULTURE
GENETICS it hard to value and take
care of their body or feel
the drastic need to

change it.

Eating disorders An emphasis on Binge eating
run in families, so may thinness in the beauty Eating large volumes of food over short periods can place
be passed on genetically, stereotypes presented in significant stress on the body’s digestive system. Most sufferers
or by learning attitudes the mass media has distorted are likely to be overweight or obese, so suffer associated health
toward food. People who the idea of an ideal body problems, including cardiovascular disease and diabetes.
have a close relative with an shape and encouraged
eating disorder are much
more likely to develop people to base self-
value on outward
one themselves.
appearance.

224 225DIETS

Eating disorders

FEMALE BIAS 20% 8% KEY
80% 92% Percentage
Eating disorders are much more BINGE EATING ANOREXIA of cases who
common in women than in men. This are women
may reflect that they are more sensitive
to the cultural pressures that can lead to Percentage
eating disorders. The proportion of men of cases who
in cases of binge eating is more than are men
twice as high as in anorexia.

Dizziness, HAIR Hair becomes dry High incidence MOUTH
depression, anxiety, BRAIN and brittle and of gum disease,
and low self-esteem may fall out sensitive teeth, THROAT
HEART
are common MUSCLES tooth erosion, MUSCLES Sore throat and
and decay inflammation of
Muscles the esophagus
become weak Muscle protein of the are common
heart itself can even
and wasted HEART begin to break down Stomach pain,
to be used as fuel, ulceration, and
NAILS weakening the heart STOMACH bloating are
Nails become BOWEL common
dry and brittle BOWEL
HORMONES Bloating and NAILS HORMONES
constipation
SKIN are common SKIN Constipation,
diarrhea, and cramps
In women, uterus may develop due to
shrinks and periods overuse of laxatives
stop; it becomes
harder to conceive

Skin becomes Increased risk
dry and scaley, of osteoporosis
and fine downy
hair may appear

BONES BONES

Anorexia Bulimia
Severe calorie restriction and a deficiency of essential dietary Although some people with bulimia may maintain a normal body
nutrients can have a traumatic effect on the body, causing serious weight, potentially they can suffer from all the health problems
health problems. Often these effects are irreversible, and if it linked with anorexia. However, they may also have additional
continues for a sustained period, anorexia is life-threatening. problems associated with frequent vomiting and laxative use.



FOOD AND
ENVIRONMENT

Feeding the world

The scale and efficiency of food production has improved Biotechnologies
over the past 60 years, due to technological advances, and High-yield, drought-resistant
in response to a growing population. Some people, however, hybrid crops and massive
still go hungry. Hunger will likely stay with us, as the more application of fertilizers,
affluent people among the world’s growing population pesticides, herbicides,
increasingly gain a taste for meat. Eating meat takes and other biochemicals
up a disproportionate amount of Earth’s resources. dramatically increased yields.
Social plans
Green revolution Mechanical improvements Consolidation of small farms into
Large scale mechanization giant ones, and small businesses
In the 1960s and 70s there was widespread concern of agriculture (such as irrigation into transnational agribusinesses,
about a looming mismatch between food supply and machines) made intensive created economies of a global
demand on a global basis in the face of a skyrocketing farming possible on a vast scale and improved yields.
global population. Books such as Stanford University scale, boosting yields.
professor Paul Ehrlich’s 1968 best-seller, The Population
Bomb, predicted a looming famine crisis. The success
of the Green Revolution saw a radical increase in
agricultural productivity. Improvements in agricultural
machinery, biotechnological chemicals, and social
collaboration were made that averted the crisis.

Rise in meat consumption Global meat and
cereal consumption
Despite the Green Revolution, we still face food This graph shows a global rise
sustainability challenges—one of which is meat eating. in total consumption of meat
Global demand for meat has increased five-fold in the and cereals to the present day
last 50 years. While meat is stable at around 30 percent and projected up to 2020.
of the diet in the West, in some developing countries,
the rate of meat consumption is skyrocketing. Farming
livestock relies heavily on the availability of water, land,
feed, fertilizer, fuel, and waste disposal capacity—and
the pressure on these resources is climbing.

KEY
Meat consumption
per capita

Cereal consumption
per capita

YEAR 2008 2010 2012

2006

228 229FOOD AND ENVIRONMENT
Feeding the world

30% DGERVAEINLOPPREODDCUOCUENDTIRNIES 800 MILLION 10
FEEDS 8
HUMANS THE NUMBER OF PEOPLE
70% IN THE WORLD WHO DO NOT
FEEDS GET ENOUGH FOOD
LIVESTOCK
Animal feed WHAT IS THE
Worldwide, animals (mainly cows) MOST SUSTAINABLE
consume an estimated one-third or
more of human grain production. In TYPE OF FOOD?
developed countries, the proportion
is even higher, at around 70 percent Probably beans—they add
of grain fed to livestock. nitrogen back into soil,

reducing or eliminating the PERCENT CHANGE SINCE 2006
need for fossil fuel-based

fertilizers, reducing
carbon dioxide
emissions.

400g (14oz) meat, 1 meal, 545 6
or two large steaks calories each 4

Efficiency of eating animals 1kg 200g TWO PEOPLE
In the US, cows eat livestock feed (grain). 1kg 1kg (7oz)
A cow has to consume more than 200g
7kg (15lb) of grain to gain 1kg (21⁄4lb) 1kg (7oz)
in weight, and 1kg of cow converts 1kg 1kg
to around 400g (14oz) of trimmed,
deboned cuts. Feeding cows grass 1kg BEEF STEAK
is more efficient—but is still far less 7KG (15LB) BAGS OF GRAIN
efficient than simply eating plants.

11 people would get
545 calories each

Efficiency of eating plants 1kg 11 PEOPLE 2
Comparatively, 7kg (15lb) of grain could 1kg 1kg 2018
feed about 11 people for a single meal. 0
Growing grain uses less space, energy, 1kg 2020
and labor than farming animals.
1kg 1kg
1kg

7KG (15LB) BAGS OF GRAIN

2014 2016

Intensive or organic? SUNLIGHT

Intensive farming on an industrial scale has helped
to keep pace with a rapidly growing population,
but at a cost to the natural environment. In response,
the emergence of organic food appeals to our
appetites, conscience, and health.

Intensive farming

In the 1960s, the Green Revolution saw biochemical advances in
agriculture (see p.228)—such as fertilizers that speed crop growth
and pesticides that protect crops from pests—both of which help produce
much higher yields. However, intensive farming has severe impacts on
surrounding ecosystems—fertilizers and pesticides can leak into the
water and soil and affect wild plants and animals. Not only that, but
there is a concern that certain foods may contain pesticide residues—
remnants of the toxic chemicals applied to crops.

Intensive farming KEY
Farming large areas means farmers have Pesticides
to apply fertilizer and pesticide over entire
fields and in large amounts to ensure that Fertilizer
the target crop plants get enough.

1 Fertilizer runoff 2 Algal blooms
Excess fertilizer from Fertilizer runoff can also stimulate
overgrowth of algae, forming algal blooms.
industrial farms is flushed off fields This dense vegetation can collect on a lake’s
by rain, and into rivers and lakes.
This causes wild plants to overgrow. surface. Algal blooms can kill off entire aquatic
ecosystems by using all of the lake’s oxygen, and
also block sunlight from reaching the lake floor.
Plants on lake
CROPS bank overgrow

FERTILIZER RUNOFF ALGAL BLOOM
PESTICIDE R
BEES Pesticides can
harm bees

1 Pesticide runoff
Pesticides sit on the plants that
we will eventually eat. These chemicals
can kill the bees that pollinate many UNOFF Plants at bottom of lake
crops. Pesticide as runoff can even be WORMS die without sunlight

carried by rain into lakes and ingested by SUNLIGHT BLOCKED
invertebrates (such as worms) that live there.

230 231FOOD AND ENVIRONMENT
Intensive or organic?

40 PERCENT OF THE What is organic food? NO ARTICIAL
WORLD’S POPULATION FERTILIZER
RELIES ON CROPS Organic foods are crops that are grown
GROWN USING without the help of artificial fertilizer NO ARTIFICIAL
NITROGEN and pesticides, and processed and stored PESTICIDES
FERTILIZER without chemical fumigants. Instead of
these, natural alternatives are used— Nutritional difference
CAN MEAT manure is a natural fertilizer, and natural There is debate over whether
BE ORGANIC? predators, such as ladybugs, can be used organic food is actually
Meat can be organic, if to control pests, such as crop-damaging nutritionally superior to
livestock are fed on organically aphids. Standards of what constitutes nonorganic food, with several
grown feed, allowed to go organic food can vary. Organic food is studies casting doubt on the
outside, not given growth appealing for those concerned about their claims. A review in 2014 found
hormones, and given health, because they are likely to have that the levels of six types of
antibiotics only if the much lower levels of pesticide residue. antioxidant (see pp.110–111),
animal is sick. on average, were higher and
69% 51% pesticide residues lower in
Pesticide in food higher higher organic foods.
can affect our
health 50%
higher

19% 26% 28%
higher higher higher

FLAVANONES
PHENOLIC ACIDS
FLAVANOLS
FLAVONES
ANTHOCYANINS
STILBENES

THE PRICE OF ORGANIC FOODS

Organic food is more expensive TRAINING
because yields are generally lower
2 Up the food chain and overhead costs are higher.
Ingested pesticides are For instance, organic dairy yields
concentrated up the food chain. Worms are generally one-third lower than
may only contain tiny amounts, but if conventional ones—so organic food
fish eat enough of them, then the fish prices are raised in order to make a DISTRIBUTION PROCESSING
profit. Extra costs can include farmer
can contain more pesticide. Animals or training, the extra cost of processing
even humans at the top of the food and storing without chemical
chain can accumulate large amounts. fumigants, a shorter shelf life of crops,
and the costs associated with a higher
instance of spoilage as a result.

PACKAGING STORING COSTS

Factory farmed
or free-range?

Intensive livestock rearing methods make meat cheaper Living space
and more widely available, but there are ethical issues A hen can be reared under various
to consider. Intensive farming has consequences for regimes (see opposite), and the
animal welfare and can even influence food nutrition. amount of space that the animal
can inhabit during its lifetime will
Ethics of intensive rearing vary depending on the country.
These are average figures from a
Intensive livestock agriculture on a large scale can be attributed to the farm in Austin, Texas.
explosive growth of confined animal feeding operations, or CAFOs.
These factory farms have very high numbers and densities of animals, Free-range hens
confined in small areas and fed grain with many enhancers and have an average of
additives, such as antibiotics and hormones. CAFOs fuel the economy
by producing large amounts of meat quickly, but at a great cost to 11sq ft (1sq m) in
animal welfare, nutritional value (see p.71), and the environment. which to roam and
Intensively farming animals causes them to suffer from stress for the
majority of their lives and this ethical issue has influenced some the option of
changes in animal rearing to keep livestock happier and healthier. going outside

DO HAPPIER
ANIMALS PRODUCE

BETTER MEAT?

Livestock such as cows and pigs Pasture-raised hens have an
that are allowed to roam outside average of 108sq ft (10sq m)
are generally less stressed—but it in which to roam
is the natural diet of grasses and

nuts they eat outside that
makes their meat more

nutritious.

Natural diet Factory diet CORN FEED
Pigs fed on their natural diet of Factory-farmed pigs are fed
leaves and nuts generally have mainly on corn, which is very high
more healthy omega-3 fatty in unhealthy polyunsaturated
acids (see p.136) in their diet and omega-6 fatty acids (see p.136)—
this means that their meat has high levels of this fatty acid can
more omega-3 in it. also be found in their meat.

OMEGA-3 GRASS OMEGA-6
FATTY ACIDS FATTY ACIDS

232 233FOOD AND ENVIRONMENT
Factory farmed or free-range?

PASTURE-RAISED Types of animal rearing

FREE-RANGE There are a confusing number of terms that can
Caged hens may be found on food. They describe farming practices,
live in spaces only but many of them mean something different to what
1/2sq ft (450sq cm) consumers may assume they mean. Even within one
big and do not category there can be wide variations. Although free-
have the option to range sounds idyllic, chickens may still live in high
roam outside densities and stay cooped up inside for most of their
lives since they only have the option to go outside for a
CAG small amount of time each day and some farmers never
actively shepherd them onto pasture. There are voluntary
farming practices that keep animals in good, healthy
conditions, but producers must join a certified program
set and checked by authorities to put welfare labels on
their produce. The table below provides a guide to the
most common labels found on beef or chicken.

ED

OVER 168 GASES TERMS DEFINITION
ARE RELEASED IN CAFO Free-range Free-range standards may simply include
WASTE, SOME OF WHICH having access—no matter how remote—to
Barn-raised outdoor space, but animals may never
ARE DANGEROUS Organic actually go outside. Chickens can live in
CHEMICALS Grass-fed high densities and can be debeaked (have
Pasture-raised their beaks removed) and cows can also
OVERUSE OF ANTIBIOTICS live in high densities.
Animals are not caged, but they are
Some farmers give antibiotics to uninfected animals as restricted indoors, kept at a high density,
a precaution against disease organsims, which thrive in are usually debeaked (for chickens), and are
crowded conditions. Because growth is stunted while an not allowed to forage or eat grass.
animal is ill, precautionary antibiotics increase the rate This primarily refers to organic feed, and to
of weight gain on average, leading to higher meat the banning of antibiotics and hormones.
production. This indiscriminate overuse of Food that is organic usually includes higher
antibiotics, however, contributes to the welfare standards such as outdoor time and
spread of antibiotic-resistant bacteria in no debeaking in chickens.
both livestock and humans. These bacteria After weaning, animals are allowed to
outcompete beneficial bacteria eat only grasses. Cows that eat their natural
and can become “superbugs” diet of grass produce meat and milk
for which we have no defense. (see p.89) that is more nutritious.
This is similar to grass-fed, although some
grain feed is allowed. Livestock are raised
outdoors, eating a selection of nutrient-
dense forage crops.

Fair trade

A tiny number of enormous global corporations dominate ARE THERE
each stage of the complex chain that brings food from ANY ALTERNATIVES?
field to plate. Powerful businesses use their influence
Some coffee roasters
to maximize their share of profits, which keeps food negotiate one-to-one with
producers, often in the developing world, in poverty. buyers (direct trade) as an
Fair trade can help farmers and businesses alike. alternative to fair trade—they

What is fair trade? do this for many reasons,
including avoidance of
The principle of fair trade can always be applied when doing business. fair trade certification

However, food can only be labeled as fairly traded if companies join a fees.

certification system that makes sure their supply chains follow strict guidelines.

These include paying their farmers and workers fairly and providing farmers in the

developing world the opportunity to sell their produce on the international market.

Fair trade food gives consumers a chance to help farmers at the other end of the

supply chain. Organizations that support fair trade work with millions of farmers

around the world, especially those producing fruit, sugar, cocoa, tea, and coffee.

FARM COOPERATIV IMPORTER

1 A farmer and some workers will 2 ETThe farm's profits are shared3Fair-trade importers minimize
grow bananas on a fair-trade ESevenly between those in thethe number of middlemen
taking a cut of the profit.
certified farm (or plantation). The local community who areION Producers and ethical
fair trade program provides
the materials they members of the farm's investors may influence
cooperative.
need. distribution.

TRANSPORTAT STORAGE SUPERMARK

4 Transportation of the bananas is 5 Bananas stored at about 57ºF 6 Most supermarkets now
organized by liaising with the (14ºC) have extended shelf stock fair-trade produce,
lives. This helps farmers sell their
transportation networks of the produce despite seasonal, but the primary driver for greater
retailers—especially big
supermarkets. environmental, and economic representation of fairly traded
foods is consumer choice
fluctuations. and pressure.

234 235FOOD AND ENVIRONMENT
Fair trade

GLOBAL PRODUCERS BANANAS GROWN IN ECUADOR AND SOLD TO THE EU

Much of the world's food supply P12R¢ICE This amount is divided among
is controlled by a few relatively twice the number of workers
large corporations. They oversee WO5R.K6E%RS than a fairly traded banana
production, distribution, and gain FARMERS
most of the profit. This means 14% 6W.O2R5K%ERS A large percentage
they influence consumer tastes, is paid to a
and, hence, demand—creating plantation owner
a difficult-to-break cycle.

PRICE PLANTATIO2N5%OWNER
25¢

SUPERMARKET This amount is
distributed among
half the workers of a

banana traded
conventionally

Fairly traded banana A large TRANCSC1OP8EO%MR4RT%MITFAUITENIROISTNIES 2.4% TRANSPORTATION
A larger proportion of the price percentage is 33%
of a fairly traded banana is paid paid to farmers
to the farmer and workers, despite
distributing a portion to the local A lower percentage
community and reserving a cut for is paid towards
the fair-trade certifiers. The retailer
benefits financially from a fairly transportation and
traded banana so that they have the shipping
incentive to promote fair trade.

A lower percentage is EU6%TARIFF A large
paid as an EU tariff IMPOR9T%ERS percentage is
RETA4I1L%ER EU12T.A5%RIFF
A lower percentage is paid toward
paid to importers transportation

A large percentage is and shipping
paid to the retailer

FAIRLY TRADED BANANA A high percentage R1IP4E.6N%ERSCONVENTIONAL BANANA
is paid as an R8E.6T5A%ILER
EU tariff

Conventional banana
Almost none of the banana's value
produced by the conventional
pathway is passed on to the
farmworkers. There are multiple
intermediate steps (within each
breakdown) between producer
and consumer, and the bananas take
weeks to get from plantation to plate.

Food fraud HORSE-MEAT SCANDAL

Food products are always in demand, but where In 2013, DNA testing revealed that
there’s money to be made there’s an incentive to in several processed foods, such as
cheat. Food fraud is perpetrated at a scale far hamburgers and preprepared
beyond most people’s imagination, with the risk lasagne meals, a substantial
of serious consequences for human health. proportion of ground meat claimed
to be beef was actually horse.
What is food fraud? Complex supply chains made it
hard to verify the origins of meat.
Food fraud can take many forms, including substitution, dilution,
origin masking, artificial enhancement, mislabeling, theft and SUBSTIT UTION
resale, brand counterfeiting, and intentional distribution of
contaminated food. The scale of the problem is unprecedented,
but the practice itself has been going on for centuries.

TION
MISLAB DILU
TUNA

TILAPIA

WHEY VEG OIL When consumers and even retailers find it hard
to identify a valuable product, it is easy for
Milk is one of the foods most commonly affected fraudsters to substitute a cheaper
by fraud. Diluting milk with cheap additives, alternative. A high proportion of foods
such as whey and vegetable oils, saves served as tuna and wagyu beef,
fraudsters money. Complex supply chains, for instance, are actually
where milk from multiple sources something else.
is mixed, makes fraud
much easier. ADDITION

ELING UNWANTED

SAND GRASS

MISLABELED HONEY Most perniciously, unwanted and sometimes
A product can be more valuable based on its toxic additives are used to bulk out food, trick
testing authorities, or as substitutes for more
point of origin. Manuka honey from New
Zealand commands a massive premium, expensive ingredients. For instance, tea
may be adulterated with used leaves,
leading to widespread mislabeling
of non-Manuka honey as the lawn cuttings, colored sawdust,
more expensive kind. and even sand.

236 237FOOD AND ENVIRONMENT
Food fraud

1.7Slippery business TRILLION US DOLLARS

In a survey in 2014–15, most
of the olive oil consumed
by Italians could not be
accounted for by any known HOW MUCH FOOD FRAUD COST
olive oil production, either
domestic or international.

THE FOOD INDUSTRYThe shortfall was most likely
cheaper oil passed off as WORLDWIDE IN 2015
sought-after olive oil.

10 14,000S Italians consumed 14,000 tons of WHAT CAN PEOPLE DO
CODNOSTMUOMENSPSTTIICON correctly labeled, domestically TO AVOID FOOD FRAUD?
0,000 TONS IMPORT produced olive oil
You can look into the supply
Italy imported 100,000 chains of the food that you buy—
tons of correctly but this may be time consuming
labeled, foreign
olive oil if the supply chain is long.
Buying from personally known
A supply gap
of 407,000 tons is suppliers that you trust
not accounted for may be the answer.
by known olive oil
sources

Olive oil fraud FAKE FISH?

When the figures don’t add up, there can be A 2013 survey by the Oceana ocean
circumstantial evidence of fraud. A case in protection group studied samples of fish
point is olive oil in Italy. Italians are among on sale around the US, using DNA analysis
the highest consumers of olive oil, but their to reveal whether the species matched the
domestic production does not come close to label. They found that around one-third of
matching this demand, especially since the samples were not what they claimed to be,
majority is exported. Even the 100,000 tons with 28 different species being sold as red
imported cannot account for the nearly half a snapper, for instance.
million tons consumed. Analysis in 2014–15
showed that lower-quality oils had been
mislabeled as extra-virgin olive oil. Fraudsters
are known to be able to pull off this trick by
adding colors and aromas.

407,000-TON SUPPLY GAP

521,000 TONS TOTAL CONSUMPTION Italians believe they Only 2 percent
consumed 521,000 of seafood is
tons of olive oil inspected for

fraud in the US

Food waste

The amount of food wasted worldwide could

easily feed all of those going hungry on our 100%
planet today. Food waste costs money and When food is wasted
damages the environment, and can happen This graphic shows how much food produced
at all stages of the food production process. on land is wasted at each stage. These are global
figures; in developing countries there is more
Effects of food waste waste toward the start of the process due to a
lack of cooling and storage capabilities so more
Food is wasted at every stage of the food is spoiled, while in developed countries,
production and supply process, and this most waste occurs toward the end of the
process because people are more able to
afford to purchase and waste food.

is a problem that affects both the developed

and developing world. Food waste costs

money and drives up food prices, and its

environmental impact is severe—3.3 billion

tons (3.3 billion metric tons) of greenhouse

gases are released from food waste to

the atmosphere every year. Water, energy, 67%
and space is wasted in producing and
distributing food that will never get –11.5%

eaten—28 percent of the world’s

agricultural land is devoted to growing

wasted food, while food garbage rots and 5 Consumption
gives off methane, a potent greenhouse gas. Much of food waste, especially
in developed countries, occurs at the
GLOBALLY, consumption stage, when food is
thrown away after it is purchased
or even after it is prepared.

ONE-THIRD OF ALL –4%
FOOD PRODUCED FOR HUMAN
CONSUMPTION IS WASTED

HOW TO REDUCE WASTE 78.5%

Even individuals can help TOMATO CARROT 4 Distribution and market
minimize waste. Steps include: POTATO Retailers throw away foods that
planning meals; preparing food are not bought by shoppers and even
in advance; freezing or reusing foods that are not aesthetically
leftovers; shopping little and pleasing to consumers (such as
often; buying food that is near strangely shaped vegetables).
the end of its shelf life; buying
produce loose rather than in
multipacks; and buying oddly
shaped fruit and vegetables (so
supermarkets do not reject them).

238 239FOOD AND ENVIRONMENT
Food waste

1 Agriculture 92% CAN FOOD
Some farmers, especially those WASTE BE RECYCLED?
in developing countries, may possess
limited agricultural resources, Food waste can be composted
infrastructure, and knowledge— into soil conditioner or

fermented using microbes to
create fertilizer. The gas

emitted during fermentation
can be collected and used
to generate electricity.

and this can lead to lower yields.

–8%

–8% 2 Postharvest and slaughter What food is wasted?
Inappropriate storage techniques
and poor chilling facilities may cause The biggest cause of waste is
some food to go bad or spoil. perishability. Foods with the shortest
shelf lives, or that are the most easily
84% damaged, are those that tend to get
wasted the most. This means that
–1.5% the more easily damaged fruit and
vegetables and roots and tubers are
wasted the most, followed by fish and
seafood that have short shelf lives.
Less meat is lost, but it takes more
land to produce meat, which destroys
natural habitats—so the environmental
impact of this waste is greater.

PERCENTAGE WASTED

45% 45% 30%
FRUIT/
3 Processing and packaging ROOTS/ FISH/
Mistakes in the processing VEG TUBERS SEAFOOD
stage can lead to further waste.
82.5% For example, milk that has been

incorrectly pasteurized (see
p.84) may be discarded.

30% 20% 20%
CEREALS DAIRY MEAT

Food miles

Until recent years, diets were limited by seasonality
and locality, but the pace of modern transportation
means that a Western shopper can buy
any food at any time—but at what
cost to the environment?

Local versus global DO GLOMBESATLOICCFGAOFHLOOBFODOADRPRRHPMOROEODRDUS UCCERS ERS USA
NEI L HOME OD
The local food movement is based on the drive to
reduce the environmental impact of industrial
agriculture. One of its most obvious goals is to
reduce pollution caused by transporting food
long distances from source to market—hence,
the concept of food miles. In fact, the true impact
of food miles is hard to unpick; for instance,
having local produce delivered to your doorstep
by a local supplier might produce more emissions
than walking to the supermarket to buy food
bulk-transported from abroad.

MORE THAN 15 PERCENT The bull’s-eye diet
OF THE FOODS Advocates of the local food movement have made this
EATEN IN THE US simple guide that prompts consumers to think about the
ARE IMPORTED zones of production they can support to reduce their
environmental footprint. At the center is what you can grow
in your own yard or even window box, while outer rings
should contribute progressively less and less to your diet.

Seasonality December January

A major driver of increased food miles in mber Febr
modern food consumption is the demand October beimyoSpntordratwEeudbSreotfrrrpoareiwmesber uary ries imported from Spain
for food at all times of year, irrespective of Nove March
whether it is in season. Fruits, for instance,
naturally have limited seasonal availability September April
in any one territory, but suppliers work
around this natural constraint by importing Domestic strawberries (UK)
foods from faraway sources, or by cold-
storing fruit on a colossal scale (many gust June Ma
“fresh” apples were actually picked y
many months ago). July
Au
British strawberries
UK strawberry growers have contrived to extend
their domestic season greatly, but suppliers still
turn to imports to keep shelves stocked for the
other five months of the year.

240 241FOOD AND ENVIROMENT
Food miles

Sourcing ingredients for pork dumplings KEY
One way to assess the cost of the Countries exporting the ingredients for siu mai
transportation involved in producing a dish is
to look at its “foodshed”—the equivalent of a (steamed pork dumplings) to Hong Kong
watershed for a river—showing all the sources
that contribute. A processed food such as siu Pork Shrimp
mai (steamed pork dumplings) produced
in Hong Kong can have a complex Rice Wheat for dumplings
transnational foodshed. outer case

Sesame oil

NETHERLANDS CHINA KOREA
GERMANY

SPAIN ITALY SOUTH
JAPAN

HONG KONG

THAILAND
VIETNAM

BRAZIL MALAYSIA NEW ZEALAND
INDONESIA

Do food miles really matter? CO2 EQUIVALANT EMISSIONS FROM
PRODUCING HALF A POUND OF EACH FOOD
Some experts doubt that food mileage is CO2 EMISIONS
the most important part of food production. 0.13lb (59g)
According to one estimate, transportation 0.15lb (68g)
contributes just 3.6 percent to food-related 0.20lb (91g)
energy use. The nature of your food makes
a far bigger impact than where it comes from. 0.55lb (249g)
Vegans have a carbon footprint dramatically 1.90lb (862g)
lower than meat eaters, because meat takes so 7.40lb (3,357g)
much more energy to produce. The local food
movement in fact targets industrial agriculture POTATO APPLES ASPARAGUS CHICKEN PIG BEEF
rather than solely minimizing food miles.

Genetically SHOULD GM
modified foods FOODS BE LABELED?

The hype, discord, and intentionally misleading This is subject to fierce
information surrounding genetically modified foods, debate. Advocates say it gives
or simply GM foods, obscures the reasoned debate consumers more control and
necessary about the risks and rewards of this new choice, but critics argue that
frontier in food production and agriculture. consumers are not sufficiently

informed to make
rational choices.

What are GM foods? R BEET
PAPAYA
Genetically modified foods are crops that have SUGA CORN
had specific genes altered or manipulated using TON
techniques of genetic engineering. Traditional SOY COT
breeding mixes hundreds or thousands of
genes at a time, but this happens over the GM foods
course of generations. New technologies make Eight types of GM foods are commercially available—
it possible to target single genes and to transfer corn, soybeans, cotton (for oil), canola (also a source
genes from one species to another unrelated of oil), squash, papaya, sugar beets (for sugar), and
organism, for instance, from bacterium to
plant. Such changes cannot be achieved alfalfa (for animal feed).
by conventional plant breeding.

Insecticide-producing Gene
switched off
genes from bacteria
TOMATO
Inserting genes inserted into corn Suppressing genes
A desirable gene
from one species is Alternatively, organisms
can be modified by
transplanted to a new switching off genes
species. Insecticide-
producing genes from so they don’t express
themselves. Some
Bacillus thuringiensis fruits, such as
have been inserted
into the DNA of corn tomatoes, have
softening genes
to produce a crop turned off so they
that makes its own BACILLUS GENE GENE GENE
insecticide. THURINGIENSIS CODE CODE CORN will last longer. This CODE
method is less common.

Why are they made? CONTROL PESTS MANAGE CROP DISEASE MANAGE WEEDS CHANGE NUTRITION
GM foods are made so that
more crops are resistant to
pests and disease, and
therefore survive to provide
higher yields. Herbicide-
resistant crops allow farmers
to use herbicide more
efficiently to kill weeds, and
crops can even be genetically
modified to enhance nutrition.

242 243FOOD AND ENVIRONMENT
Genetically modified foods

The GM debate

Despite the flourishing culture of anti-GM food

opinion and activism, there are no well-supported

or scientifically respectable large-scale studies

to support claims that GM foods pose a risk to

human health. The rational counterargument ARGUMENTS FOR GM

is that GM foods comprise a colossal public Good or bad?
Supporters argue that there
health experiment without informed are real and potential benefits
to GM foods, but there are
consent and with unknown long-term biological, environmental, and
economic concerns to consider.
outcomes. The spread of new, Here are just some of the
arguments for and against.
altered genes into wild populations
ARGUMENTS AGAINST GM
also has unknown effects on
Risk of disease
the environment. Meanwhile, Options for vegans Some GM crops are
the food industry has moved Plants could contain meat monocultures (genetically
on without waiting for the and dairy components identical) and this genetic
debate to settle—GM foods (such as vitamin B12) if they similarity means they all may
are commonplace in had the genes for them. be equally vulnerable to the
countries such as the US. same infectious disease.
This could open up new
dietary possibilities
for vegans.

Fewer chemicals
Pest-resistant, fast-growing
GM crops mean there is a
reduced need for pesticides
and fertilizers, which

benefits the environment
(see pp.230–31).

Global demand More chemicals
Modifying crops that are If GM crops are bred to
adapted for difficult and be resistant to weed-killer
changing conditions, chemicals (herbicides), farmers
with enhanced nutrition, are free to use more herbicide,
will be necessary to which can kill natural plants
living around the farm and
meet the demands cause wide environmental
and changing needs damage downstream.
of a growing
population. Corporate power 90 PERCENT
GM foods are produced OF SOY, CORN,
using genetically modified COTTON, CANOLA,
organisms (GMOs), and are AND SUGAR BEETS
generally patented and have to SOLD IN THE US HAVE
be bought anew each growing BEEN GENETICALLY
season. They are controlled by a ENGINEERED
handful of major multinationals.

Overfishing and
sustainable fishing

Fish are more popular than ever, partly due to the increasing
awareness of their health benefits. But the world’s insatiable appetite
has almost drained the once apparently limitless resources of the
ocean—often with catastrophic results to ecosystems. Fish farming
and sustainable fishing may provide solutions to these problems.

Global hunger for fish IS IT OK TO
EAT TUNA?
Around three billion people in the world, in order to obtain enough
protein, rely on either wild-caught or farmed seafood, including The once-abundant bluefin
fish. On average, each person eats four times as much seafood now tuna is now critically endangered,
than they did in 1950. To satisfy this great demand, global fisheries
have already been pushed past their limits. When fish stocks and many other tuna species
(populations) fall steadily, they are being overfished—and this is are decimated. They are large
unsustainable because these fish will, sooner or later, become too predators, and so like big cats or
scarce to support a fishery—or worse, become extinct entirely. birds of prey, they are naturally
The United Nations Food and Agriculture Organization (UNFAO) scarce—so we can’t eat them
says we will need another 40 million tons (36.3 million metric tons)
of seafood worldwide per year by 2030 just to meet current too much or too fast.
consumption rates, based on current population projections.

A rise in fishing
Since the 1950s, global fishing of wild
populations (wild fisheries) has been rapidly
increasing, along with aquaculture (fish farming).
By the 1990s, fishing plateaued as fish stocks
became depleted. In response, fish farming grew
even more rapidly—and continues to grow.

KEY
Fish farming

Wild fisheries

84 PERCENT OF FISH
STOCKS ARE EITHER FULLY
EXPLOITED OR OVERFISHED

YEAR 1960 1970
1950

244 245FOOD AND ENVIRONMENT

Overfishing and sustainable fishing

How to fish sustainably NO-CATCH AREAS NO BOTTOM TRAWLING PREVENTING FRAUD 160
REDUCE BYCATCH SUBSTITUTION OF STOCKS 140
Sustainable fishing preserves fish 120
populations and allows them to LINE-AND-POLE Are fish farms the solution? 100
replenish themselves. It involves a Fish farming involves raising fish and other
mixture of good practice, such as: seafood in captivity, usually in giant ponds
no-catch areas, where fishing is or netted enclosures. Whether fish farming
illegal; no bottom-trawling, to is sustainable or not depends on whether
avoid damaging fragile ecosystems the fishmeal they are fed was sustainably
such as reefs; preventing fraud, in fished itself.
which fishers misreport catches;
reducing bycatch by using nets
that allow fry and other
accidentally caught species
to escape; buying other species
of fish that are not overfished;
and fishing using a line and
pole, which targets individual
fish rather than entire schools.

FISH LANDINGS IN THOUSAND TONS 80
GLOBAL FISH LANDINGS IN MILLION TONS
COLLAPSE OF ATLANTIC COD STOCK

One of the most dramatic instances 725 Factory ships Canada 60
of a fishery collapse was the Grand 540 cause spike in suspends 40
Banks cod fishery off Newfoundland. 360 cod fishing
Cod were once so plentiful in the 180 cod catches in the
area that it was possible to scoop region in
them out of the sea with a basket. 0 1992
The implementation of factory ships 1900
in the 1960s caused a massive spike 20
in catches, but they quickly declined
and fell completely in the 1990s. 1925 1950 1975 2000
Recovery is slow because cod fry are YEAR
quickly eaten by predators. Adult cod
would normally eat the predators
of the fry, but since they are absent
very few cod ever grow up.

1990 2000 2010

Future foods

The technology behind food production and 2 Sun’s energy
agriculture continues to improve, bringing Surface seawater
about more efficient, sustainable ways to runs through pipes along
produce food—on both large and local scales. the greenhouse roof where
it is heated by the sun. Solar
panels harvest sunlight to
generate the electricity to
power the fans and pumps
Farms of the future that move the seawater.

Tomorrow’s farms will have to feed a rapidly growing population

that will demand more and better food. They will also have to cope

with climate change, soil degradation, water shortages, non-native

pests, and new diseases. To overcome these challenges and meet 3 Air humidified
The hot seawater
these needs, innovative solutions are already being explored,

by retooling the agricultural wisdom of ancient cultures, runs down another
porous wall. The cool,
or by creating entirely new, controlled systems. moist air is drawn
Seawater

Seawater greenhouses heated by sun through this wall, and
For hot, arid seaside regions where crops as it passes through it is
are unable to grow, seawater greenhouses Seawater heated and can pick up
produce a hospitable growing climate trickles down even more moisture.
and create freshwater with absorbent wall
which to irrigate crops.

Cool, moist air creates Hot seawater
favorable growing conditions drips down
Dust MOISTURE
Hot air saturated
with moisture

HOT, DUSTY AIR COOL, MOIST AIR FAN
CONDENSER
1 Using seawater Freshwater irrigates crops CROPS
Surface seawater is
pumped and cascaded down a Freshwater
condenses

porous, absorbent cardboard
wall. Hot air from outside is
drawn through the wall by
airflow created by fans—it is
cooled and saturated with
moisture as it passes
through the
wet wall.

Seawater drains
back to the sea

FRESHWATER STORAGE

SURFACE 5 Irrigation 4 Freshwater condenses
SEAWATER The freshwater is used to irrigate Deep, cool seawater is pumped
DEEP SEAWATER the crops in the greenhouse, and also
any additional crops in the surrounding through a series of vertical pipes into
SEAWATER DRAINAGE the condenser. When the hot, humid air
area. A wide range of produce can be from the greenhouse meets these pipes,
grown, as in a traditional greenhouse,
including tomatoes, cucumbers, peppers, freshwater condenses onto the surfaces of
the pipes, which then collects in a storage
lettuce, strawberries, and herbs. The tank. The salt from the seawater can be
whole process is controlled by computer.
collected as a useful byproduct.

246 247FOOD AND ENVIRONMENT
Future foods

New sources of meat GREENHOUSES ON MARS

The growing demand for meat around the world— Martian soil contains most of the nutrients
and the inefficiency with which some countries needed to grow plants, but there is almost no
raise their livestock (see pp.228–29)—means atmosphere on Mars, freezing temperatures,
there is an urgent need for alternatives. Insects no running water, and damaging radiation.
are already eaten by many (see p.148) and could Greenhouses have been proposed that might
be a more sustainable source of meat. Not only is be able to concentrate the sun and trap gases
80 percent of a cricket’s body edible, compared to to create growing conditions.
only 40 percent of a cow’s, there is actually more
protein in 31⁄2oz (100g) of cricket than in beef.

80 percent 40
edible percent
edible
CRICKET COW

Reimagining ideas PLANTS
Natural fertilizer
Medieval Aztecs used to raise crops without soil whilst Microbes and composting worms
suspending them above lakes. Today, aquaponics does feed on the fish waste and turn
something similar. It is an agricultural system that it into a natural fertilizer for
combines fish farming and growing plants without soil. the suspended plants.
It functions independently—and therefore could be a
more sustainable way to farm fish and raise crops.

SCIENTISTS IN JAPAN ARE
WORKING ON A KITCHEN
THAT PROJECTS PREPARATION
INSTRUCTIONS ONTO FOOD

FISH WASTE FISH
Food source Cleansing
The waste the fish produce Plants are grown in the same
provides a food source water as the fish. They
for microbes and filter the water, which helps
composting worms. keep the fish healthy.

Index ale 173 in soy sauce 103 battle butties 58
alfalfa 242 in tea 157, 184 beans 100–01, 106, 126, 229
Page numbers in bold refer algae 81, 149 in vegetarian diets 189 beef 26, 65, 68, 72–73, 81, 101, 113,
to main entries. algal blooms 230 aphids 231
alkaline diet 204–05 aphrodisiacs 80 189, 229, 247
5:2 diet 200–01 alkaloids 55, 111 appetite 14–15 beer 165, 166, 172–73
allergies 206–07, 210 apples 122, 158 beets 109, 117, 135
A allicin 118 fiber 24 beige fat 191
alliin 119 freshness 46–47 berry fruits 123
acai berries 109 alliums 118 seeds 122 best before 47
acetaldehyde 166, 167, 168 almonds 108, 109, 126 vitamins 41 beta-carotene 107, 116, 120
acidity regulators 59 alpha-linolenic acid (ALA) 78 APT 23 bifidobacteria 87
acrylamide 95 alternate day diet 200–201 aquaponics 247 bile 20, 21, 25, 30, 31
additives 58–59 alternative foods 148–49 arabica coffee 154 binge eating 224, 225
Alzheimer’s disease 193 aromatic oils 130 bioavailability 115
alcohol 169 amaranth 92, 93, 109 arsenic 223 bioreactors 149
animal fodder 232 amino acids 13, 26–27, 63, 69, 103, arteries biotechnologies 228
carbonated drinks 160 and blood pressure 213 birds 148
convenience foods 39 162, 163, 190, 191 and cholesterol 31, 214, 215 birth defects 221
and intolerances 208 intolerance to 208 Asian cuisine 184 bitter taste 17, 19
processed foods 57 ammonia 76, 77, 100, 101 aspartame 16, 138 black tea 156, 157
tap water 152 amylopectin 90, 91, 104 Aspergillus flavus 125 blending 159
unwanted 236 amylose 90, 91, 93 asthma 182, 206 blindness 42
whole foods 40 anemia 12, 33, 35, 167, 218, 219 astringency 17 bloating 208, 209
adenosine 163 anaerobic exercise 192 atheroma 215 blood
adipose tissue 15 anaphylaxis 206, 207 Australian diet 139, 177
adrenaline 27, 163, 207 anatomy, evolution 8 autoinjectors 207 alcohol in 168, 169
aerobic exercise 192 anethole 130 avocados 108, 109, 121, 208 water in 36
aflatoxins 125 animals blood clots 31, 118, 215
agriculture 228, 246 fasting 201 B blood glucose levels 91
factory farming or free-range rearing conditions 232–33 blood pressure
welfare 187, 188, 233 babies 222 diet and 212–13
232–33 anorexia 224–25 Bacillus cereus 65 exercise and 193
fair trade 234–35 anthocyanins 106, 123, 170 Bacillus Thuringiensis 242 garlic and 118
food waste 238, 239 anti-caking agents 59, 134 bacteria high 31, 134, 135, 155, 163,
GM foods 242–43 anti-inflammatories 115, 133, 184
history 9 antimicrobials 48, 74, 184 antibiotic resistant 233 212–13, 214
intensive 228, 230–31, 241 antibiotics 87, 206, 208 and cooking 64, 65 low 36, 159, 196, 201
organic 230, 231 for livestock 231, 232, 233 fermenting 86–87, 144 blood sugar levels 14, 23, 91, 101,
air freight 46 antibodies 33, 99, 206–07 and freezing 50 140–41, 162, 216, 217, 221
airplane food 19 antihistamines 207 and freshness 47 blood vessels 118, 159, 168, 215,
alcohol 164–65 antioxidants 32, 33, 35, 40, 111 in gut 25, 189, 199 216
abuse 167 additives 58, 160 and immune system 206 blood-type diet 204–05
beer 172–73 in alcohol 165, 170, 171, 172 pasteurization 56, 84 blueberries 108, 109
and the body 164, 168–69, 212, in cocoa 145 starter cultures 95 BMI (body mass index) 68, 190
in eggs 82 vitamin production 25 BMR (basal metabolic rate) 192–93
215 in fruit and vegetables 104, 106, baking 60, 95 body
and cancer 219 baking powder 142 alcohol and the 164, 168–69, 212,
fermentation 52 107, 108, 109, 112, 113, 115, 118, baking soda 94, 135, 142, 147
in pregnancy 221 121, 122, 123 balanced diet 12, 13, 176–77, 194 215
prohibition of 186, 187 and heart disease 215 bananas 51, 91, 122, 125 fats in the 29
spirits 166–67 in herbs 133 fair trade 234–35 nutrition 12–13
wine 170–71 instability of 48 barn-raised 233 see also health
yeast and 125 in raw food 54 basil 133 body dysmorphic disorder 224
alcohol by volume (ABV) 166 in smoked food 48, 74 boiling 60
alcoholism 169 bones
exercise and 193