How Food Works

148 149TYPES OF FOOD
Alternative foods

New foods COULD WE USE
FIBER AS FOOD?
Any new food needs certain characteristics if it is to become
a practical addition to the human diet: it must be safe, a good Although we cannot digest
source of nutrients, economic to produce, and, ideally, have fiber, scientists have found
a small ecological footprint. A good starting point is to try to a way to convert cellulose
adapt existing foods, such as lupin beans and algae, although (a major component of fiber)
scientists are also trying to grow meat from into starch that we can digest
animal muscle (see below).
and so could potentially
Algal flour be used as food.

Lupin plant
Lupin bean

Algae Lupin beans 20,000
Large algae—seaweeds—are Lupin beans are already part of
popular food items in Asia, but some cuisines but they have also THE NUMBER OF EDIBLE
some microscopic algae have also been used as the raw material to PLANT SPECIES WORLDWIDE
been cultivated and used to make produce synthetic vegetable protein
foods such as algal flour. foods, such as lupin meat and flour.

Stem cell Sheet of
on scaffold cultured meat

BIOREACTOR BIOREACTOR

Scaffold for stem cells Nutrient medium Final cultured
meat product

3 Stem cells placed on scaffolds 4 Cultured meat produced 5 Cultured meat processed
The stem cells are placed on frames Bathed in a nutrient liquid in the The thin sheets of meat are removed
called scaffolds so that they have a surface bioreactor, the cells grow into sheets of from the bioreactor and processed into
on which to grow. The scaffolds, which meat. The sheets are very thin (about thicker slices. Additives, such as colorings,
are biodegradable and edible, are then 1mm/0.04 inches) and need processing flavourings, and fat, are mixed in to make the
placed in a bioreactor. into larger, edible pieces. meat look and taste like natural meat.



DRINKS

Drinking water WHAT ARE
ELECTROLYTES?
Clean, safe water from the faucet is one of the great In food science, electrolytes
achievements of civilization. Bottled water has refers to dissolved minerals
become increasingly popular, but there are concerns or salts. The body needs
about its environmental impact and no concrete electrolytes such as sodium,
evidence that it has health benefits. potassium, and chloride for
normal functioning of its
Treatment of tap water Water tissues and cells.
The purpose of water treatment agitator
is to remove dirt, debris, toxic COAGULANTS
chemicals, and microbes to
produce water safe for human
consumption. The details of the
treatment process vary from
region to region, depending on
water standards, but it typically
involves the stages shown here.

2 Coagulants added
Chemicals, such as aluminum
sulfate and iron chloride, are mixed
into the water to make dissolved
RESERVOIR particles come out of solution and

clump together—or coagulate—with
particles of dirt.

1 Water from source Larger clumps
Water for human consumption is of particles
drawn from lakes, rivers, reservoirs, and
boreholes. It is screened to sieve out large
debris and organic matter that would
otherwise clog up later processing stages.

SLUDGE LAYER

Tap water 3 Settling
Under gentle mixing, the
In developed countries, tap water is thoroughly treated to remove coagulated particles cluster together
dirt, microbes, and toxic contaminants. It is also rigorously tested to form large clumps, a process
to ensure it remains safe to drink and cook with; in fact, the known as flocculation. These clumps
testing may be to a higher standard than that for some bottled settle out to the bottom of the tank
waters. In addition to ensuring safety, water treatment may also (sedimentation), where they form a
include adjusting the acidity or alkalinity of the water, so that it layer of sludge that can be removed
does not corrode pipes. Tap water may have certain substances and treated for use as fertilizer.
added to improve health—for instance, fluoride to reduce tooth
decay—but any such additives vary according to local regulations.

152 153DRINKS

Drinking water

Mineral water Bottled water

Mineral waters were traditionally drunk at their Bottled water is not necessarily from a spring
natural sources, such as spas or wells. Now, they are
more commonly bottled at the source and distributed or other natural source. Many bottled waters
for sale. They often have high levels of dissolved
minerals, although these do not necessarily confer essentially come from the tap, and some are not
health benefits, and they must have a consistent
composition and be safe to treated in any way. Bottled water is typically sold
drink without any treatment.
Spring water also originates in plastic bottles, and there are concerns about
from a natural source, but its
composition may vary and it the environmental impact Less than 1%
may be filtered or treated. of the packaging: the treatment at plant
bottles need a lot of
energy and other Less than 1%
resources to make, filling, labeling,
and they also create and sealing
bottle

a lot of waste. 4%
refrigeration

Mineral-rich water SPA WATER Energy in a bottle 45%
from natural spring FOUNTAIN Only a fraction of the energy transportation
cost of producing water in a
Spa water plastic bottle comes from 50% production
Many spas historically developed around treating and bottling the water. of plastic bottle
natural springs, where the mineral water was The vast majority is used in
believed to be beneficial for health, both making the bottle and
when drunk and also when bathed in. transporting it for sale.

4 Filtration 35BILLION
The water is then passed
through beds of increasingly fine THE NUMBER OF PLASTIC
gravel, sand, and charcoal to WATER BOTTLES THROWN
IMPURE WATER remove remaining particles AWAY EVERY YEAR IN THE
and microbes. US ALONE
Fine gravel
Sand PARTICLE 5 Disinfection and storage
FILTER Chemicals are added to
Charcoal
CLEAN WATER the water to make sure it is not
acid or alkaline and to destroy any
remaining microbes. The water is 6 Public water supply
then stored, ready for distribution. Water is distributed to homes and
businesses through public water pipes.
Water that will pass through lead pipes
sometimes has additives that prevent lead
from leaching into the water.

ADDITIVES DISINFECTANTS

STORAGE
TANK

DRINKING
WATER

WHAT’S THE 1 Harvesting
DIFFERENCE When a coffee plant is five
BETWEEN ARABICA AND years old or more, its berries can be
ROBUSTA COFFEE? harvested. They are picked when
they have ripened from green to red.
Arabica has a more delicate,
sweeter flavor and is slower COFFEE
PLANT
growing—and so, more
expensive—than robusta,

which has twice
the caffeine.

From berry to bean 2 Processing
The ripe berries are processed
Coffee is an infusion of ground, roasted to remove the outer skin, pulp, and
beans that come from inside the berries parchment. The end result is raw
of shrubs belonging to the Coffea group of green beans.
plants. Once the berries have ripened on
the bush, they are picked and the pulpy Parchment
flesh must be removed from the beans
within. Sometimes they are left to dry and
ferment in the sun before the pulp is
removed; another method is to remove
most of the pulp first and then ferment the
bean. They are then washed and dried.

Bean BEANS PROCESSED

Pulp

Coffee 3 Roasting
The green beans are roasted
Every day, more than two billion (typically in a large drum) to bring
cups of coffee are drunk by people out the characteristic coffee aroma
all around the world. It is valued and taste.

for its stimulant properties,
and for its complex flavors
and aromas.

DRUM ROASTING

154 155DRINKS
Coffee

How much caffeine? Espr Bre wed decaffeina ino Espresso Caffeine on the menu
On 8fl oz ted ated The longer coffee is brewed, the more
Although tea leaves contain 1fl oz caffeine is extracted. The espresso
more caffeine than coffee beans (240ml) (30ml) method forces hot water through
(2–3 percent against 1–2 percent), 2–12mg 47–75mg grounds at high pressure, mobilizing
in brewing, much more caffeine is the volatile, flavorful oils without
extracted from coffee than from tea. esso decaffein e-shot cappucc extracting as much caffeine.
A typical cup of coffee may contain 1fl oz 8fl oz
about 50–100mg of caffeine, compared (30ml) Brewed
to 20–50mg for a cup of tea. Different (240ml)
methods of brewing can radically 0–15mg 47–75mg 8fl oz
alter the amount of caffeine that (240ml)
is extracted from ground coffee. LOW 95–200mg

10 MILLION TONS 8fl oz CAFFEINE HIGH
OF COFFEE WERE (240ml)
PRODUCED IN 2015 tant2d–1e2cmafgfeinat 8fl oz
(240ml)
Ins ed 27–173mg
Instant

HOW CAFFEINE AFFECTS THE BODY How instant BREWED
coffee is made COFFEE

Caffeine is the most widely consumed psychoactive Instant coffee is coffee that FREEZER AND
substance (one that alters mental processes) in the has been brewed and then GRANULATOR
world. The most notable effects of caffeine occur dried to a powder so that it
after consumption of low-to-moderate amounts can be reconstituted simply
(50–300mg—the recommended daily limit is 400mg). by adding water. There are
They include increased alertness, energy, and ability two methods for doing this:
to concentrate. Large amounts can lead to negative either the liquid coffee is
effects, such as anxiety and insomnia. sprayed into a hot, dry
atmosphere through a tiny
Brain Stomach nozzle to give a superfine VACUUM Water
Relieves fatigue; Excessive mist, which quickly dries into CHAMBER drawn out
consumption powder, or liquid coffee is of frozen
can lead to linked to frozen and then freeze-dried, coffee
anxiety or heartburn with the water turning granules
insomnia directly from ice to gas.

Heart and Kidneys Freeze-dried coffee
circulation Diuretic; All types of instant coffee lose
Raises blood increases risk flavor and caffeine during
of kidney manufacture, but freeze-
pressure; stones drying preserves more of
increased risk the aroma compounds.

of irregular
heartbeat

INSTANT
COFFEE
GRANULES

Tea DOES TEA
HAVE LESS CAFFEINE
The world’s most popular brew has a rich
history, stretching back thousands of years, THAN COFFEE?
and an equally rich store of nutrients. There
are many types of tea, from black to white. Although tea has a higher
caffeine content than coffee,
The main varieties WHITE usually less makes it into the tea
Tea varieties are determined by the infusion—50mg per cup of tea
maturity of the leaves when picked,
and the degree and duration of compared to 175mg
their processing. per cup of coffee.

MYpaEatraLuolnlLrolelfhOewifrldedeeeeWarraddaimtven,itnedldeoigsgnsd,pahotarartaminelreyftdtdeiea,tmrlhlyeonre. Buds or young occnaueofnrnirdfszee,sMydrdtthmmeratieaoeeetmnudnsdr,r.teeeosadGoatllliecoeotRathdrnivvEapeatEastneNare HERBAL TEAS
leaves are steamed
Herbal teas are made from
to deactivate the infusion of herbs, spices,
enzymes and or fruit extracts in hot water.
prevent more than To distinguish it from a
light fermentation, “true” tea, a herbal tea may
also be referred to as a
then dried. tisane, or infusion. Taken
hot or cold, they do not
ABfmtuaeLrlaaalAeyt,nuswmCfdere(eivKoarltfeemhdrlierrfeeotaieanrlxtnfvegorhietddoeoasf,imedznurtrehodrm)salldftebeordnerytfionrge. OOLONG thhueofenaurtdgminehAlergitgfknleoasoetoanraey,dltksoepinoslrnuloeonoPg-clwewelaUoirrnfnhn.tt-geedaEt,aresaR,ardy,Hark contain caffeine.

Said to be semi-
fermented, this tea is
made from withered
mature leaves that

are bruised and
fermented for a short

time, before being
pan fired and dried.

Types of tea 38

Tea most commonly refers to an infusion of dried PERCENT OF TEA
leaves of a camellia bush (Camellia sinensis, not the IS GROWN IN CHINA,
garden variety). The basic preparation of dried mature THE LARGEST PRODUCER
leaves is green tea. Freeing enzymes in the cells of the OF TEA IN THE WORLD
tea leaves produces darker teas, transforming simple
phenols into more complex ones—a process commonly
but mistakenly called fermentation.

156 157DRINKS
Tea

What is in a cup of tea? F VITAMINS
Green tea
Green tea is rich in colorless, Polyphenol CHINSSAPONINRelaxant amino
bitter, but not astringent flavonoids are Foaming, contains vitamin C acid with strong
phenols called catechins. thought to have Santimicrobialand B2, along with
In the production of black antioxidant andLAVONOIDS agents, said to umami and
tea, enzymes released during immune-boosting lower blood folic acid and sweetness flavor
rolling and bruising of the pressure and fight water-insoluble characteristics
leaves and oxidation convert properties tooth decay THEANINE
most of the catechins into vitamin E
theaflavins, which give black
tea its slightly bitter, astringent Rich in CATE
flavor. Tea also contains caffeine, potassium,
theanine, flavonoids, saponins, calcium,
vitamins, and minerals. phosphorus and XANTHINE DERIVATIVES The most
magnesium, and prevalent types of
Green tea phenol flavonoids in
The color of green tea comes from other trace Caffeine and green tea; may be
the chlorophyll in the leaves. This is minerals other xanthine- anticarcinogenic
preserved because the leaves undergo MINERALS derivatives, such as
little processing, and it is not masked theobromine, are
by dark phenols. stimulants

Water, steeping times, HERBAL °C BLACK Cooling down
and temperatures 3–5 mins 100 °F
GREEN A hot drink can actually
Brewing the perfect cup of tea 90 220 help you to cool down on
is an art and a science. The final 1–2 mins 80 2–3 mins a hot day, by increasing the
brew should be slightly acidic— YELLOW 70 amount you sweat. Although
with a pH close to 5—so it is best 200 the drink raises your core
to start with water that is neutral, temperature, the net effect
and with a moderate mineral 190 OOLONG is heat loss.
content. Mineral water may be
better suited than tap water in 180 More sweat Core body
2–3 mins produced temperature
many regions. While larger on skin increased
flavor compounds 170
emerge slowly,
and at higher WHITE
temperatures, 160
in green tea,
cooler water limits

the extraction of bitter
and astringent compounds.

Optimum conditions 3–6 mins 1–2 mins
Different types of tea are best
prepared using particular water
temperatures and brewing times.

Fruit juice and GRAPE FRU IT PU RE JUICE
smoothies
32 grapes Juice of
One of the hottest diet fads is the 0.5oz/15g 64 grapes
extracting and blending of healthy 1.27oz/36g
ingredients to make easy-to-consume
drinks. Although juices and smoothies
have much to recommend them, the
hype masks some potential downsides.

Fruit and vegetables versus juice ORANGE 1 orange Juice of 3 oranges
0.4oz/12g 0.75oz/21g
While juice is often touted as offering the health
benefits of fruit and vegetables, in fact, juices differ PINEAPPLE 1 slice Juice of 3 slices
significantly from the whole foods from which they are 0.25oz/8g 1oz/28g
made. In addition to removing the beneficial insoluble
fiber from fruit and vegetables, juicing removes their
texture and, especially in vegetables, strips away the
structure that can actually have a cleansing action
on teeth. In fruit juice, all the sugar from a large
amount of fruit is concentrated into a much smaller
volume, resulting in a very high sugar content. The
sugars are liberated and immediately available to
bacteria in the mouth that contribute to tooth decay.

Solid or liquid? KEY GRAPEFRUIT Half a grapefruit Juice of 1 grapefruit
A small glass of orange juice contains Portion of 0.3oz/9g 0.6oz/18g
almost all the fruit sugar (fructose) of fruit eaten
three medium-sized oranges—more whole
oranges than most people would eat.
Furthermore, it contains only a very Portion of
small fraction of the fiber content. fruit in a
glass of juice

IS FRESHLY Sugar (oz/g)
SQUEEZED JUICE
BETTER THAN JUICE FROM APPLE 1 apple Juice of 3 apples
CONCENTRATE? 0.6oz/18g 0.85oz/24g

There is no difference in the POMEGRANATE Half a pomegranate Juice of 2 pomegranates
nutritional value of juice from 0.4oz/12g 1.1oz/32g
concentrate. If sugar has been
added, however, it will raise

calories and the risk of
tooth decay.

158 159DRINKS

Fruit juice and smoothies

More nitrates Smoothies Sugar spike
Green smoothies are high in Blending ingredients increases
nitrates, which can help to their glycemic index, meaning
that the body absorbs their
dilate the body’s blood
vessels and reduce sugars more quickly. Adding
blood pressure. greens to smoothies can
counteract this.
More
fruit and Smoothies are blended
vegetables
Smoothies can whole ingredients, often
help us to meet
the five-a-day promoted as health foods, because
target of fruit and
vegetables, but are unlike juices, they retain the fiber of
better used as a
complement rather than the whole food. In practice, there are
to replace whole
PROS nutritional pros and cons. On the one hand, CONS Tooth decay
meals. they can encourage the intake of fruits and A flood of fruit sugars and
More vegetables, and blending can help to break the lack of beneficial texture
down cell walls, releasing more nutrients. increase the risk of tooth
phytochemicals
Using whole fruit On the other hand, they can lead to the decay. Rinsing your mouth
and vegetables in rapid intake of large amounts of with water can help
a smoothie helps you avoid this.
to boost fiber
intake and that of sugar. Store-bought smoothies
phytochemicals
attached may even contain Kidney
added sugar. stones
to fiber. Green
Smoothie sense smoothies
The faults in smoothies can be can be high in
counteracted by the way you make compounds
them. Adding greens, such as spinach called oxalates,
or celery, can not only accentuate the which increase
benefits, but also reduce the drawbacks, the risk of kidney
such as blood-sugar spikes.
stone formation.

Fruit juice versus 12 0.12 BLENDED SOUPS
soft drinks
Sugar content (g/100ml) 8 0.08 Sugar content (oz/fl oz) At least one study backs up the
Fruit juices may not be claim that soups can fill you up
much healthier than soft 4 0.04 more than solid foods taken with
drinks or energy drinks. They water. This implies that blended
contain comparable levels of soups stay in the stomach longer,
sugar and can take daily sugar inhibiting the release of ghrelin,
intake to levels that contribute the “hunger hormone,” so that
to obesity and diabetes, appetite is suppressed.
especially in children.
00
Sugar content of drinks Energy Soda Orange
Energy drinks can contain amazing drink juice
quantities of sugar. While a typical can of
soda contains around seven spoonfuls,
orange juice is not that far behind.

Carbonated drinks Additives ADDITIVES 3% ANTIOXIDANTS
The additives in sodas PRESERVATIVES
Many people enjoy carbonated drinks as a regular are mainly colorings and COLORINGS
part of their diet. Although they are mostly water, flavorings, but also acids (citric FLAVORINGS
they contain a significant quantity of sugar and have and phosphoric acid) to add ACIDS
been implicated in a number of health problems. “sharpness,” preservatives, EMULSIFIERS
emulsifiers, and antioxidants.
What is in soda?

Typically, a carbonated drink starts as a “simple syrup” of sugar
and water. The other ingredients are then added in a specific order
to give what is called the “finished syrup.” This is diluted with
water, carbonated, and bottled (or canned). For some bottled drinks,
carbonation is done after bottling, just before the bottle is sealed.

Under pressure

Putting the fizz in a drink is achieved by bubbling carbon dioxide gas through

the liquid under high pressure, so that the carbon dioxide dissolves. When the

pressure is released, the carbon dioxide forms gas bubbles again.

KEY Bottle When bottle is opened, SUGAR 7–12%
cap keeps carbon dioxide forms
Carbon pressure bubbles of gas Sugar
dioxide on dissolved A typical soda contains up to
(CO2) carbon TONGUE 12 percent sugar. In a 11 fl oz
dioxide (330 ml) can of regular soda, this
Water in water Carbon dioxide equates to about nine
(H2O) bubbles burst teaspoons of sugar. In
on tongue diet soda, some or
all of the sugar is
replaced with
sweeteners.

Containing the fizz Feeling the fizz
The carbon dioxide remains dissolved because Opening the bottle releases the pressure, allowing
it is kept under pressure. Some of the dissolved the carbon dioxide to become a gas again.
carbon dioxide forms carbonic acid. Carbonic acid in the liquid gives a “sharp” taste.

Supersizing drinks WATER 85%

The introduction of cheap sugar alternatives in the 1970s led to an Water
increasing supersizing of soft drinks. Previously, drinks came in Water makes up most of a
6.5fl oz (190mL) bottles, but the standard can now contains 110fl oz soft drink. Usually taken from
(330mL). As a result, people are often consuming significantly the city water supply, the
more calories in drinks than they could possibly eat. water is filtered and
treated to remove solid
Movie theater-sized Butter not particles and microbes
portion is equivalent to included in before adding sugar
three standard cans calories and additives. After
this, the liquid is
LARGE SIZE 2 BAKED POTATOES carbonated.
CARBONATED 5oz (200g)

DRINK
32fl oz (940mL)

364 CALORIES 376 CALORIES

TRUCKS TRANSPORTING DRINKS
SODA HAVE TO DISPLAY THE
HAZARD WARNING SYMBOL Carbonated 160 161drinks
FOR HIGHLY CORROSIVE MATERIAL

Rotting the teeth Tooth staining and decay TOXIC TONICS
The sugar in soda contributes
It is not only the sugar in sodas to the buildup of plaque, which Sodas began as health tonics, based on the
that is bad for you; they also can lead to staining and decay. widespread belief that carbonated spa
contain three acids—citric, waters were healthy. Cola drinks began
carbonic, and phosphoric. These as a mixture of wine and cocaine until
all have an average pH of 2.5, Prohibition in 1886, when the wine was
which is slightly stronger than replaced by soda water. Cocaine remained
stomach acid. These acids erode until 1904, when its addictive qualities
the enamel of teeth, exposing became a matter of concern.
them to microbial attack and
subsequent decay.

Energy drinks CAN PROTEIN

Manufacturers’ claims have driven the explosive SHAKES REPLACE
growth of the energy drink market. Positioned at the MEALS?
intersection between soft drinks and supplements,
energy drinks struggle to back up their boasts. Protein shakes can be an
effective meal replacement as

part of a balanced diet, but

Types of energy drinks they lack the essential vitamins
and minerals of a
Energy drinks are soft drinks that claim to boost energy levels. They

usually have high levels of caffeine and sugar, and may contain electrolytes complete meal.

(mineral ions, such as sodium, normally dissolved in the blood). Many

feature amino acids, herbal extracts, and other ingredients claimed to have

health benefits. The market has diversified to include sugar-free varieties

and concentrated versions in the form of shots and gels. Drinking them

with alcohol increases the risk of overindulgence and dehydration.

GUARANA SEEDS HAVE
TWICE AS MUCH CAFFEINE
AS COFFEE BEANS

The verdict ENERGY DRINK Real benefits? SPORTS DRINK
Packed with caffeine Sports drinks differ
and usually full of Main ingredients: in electrolyte levels Main ingredients:
sugar, energy drinks Stimulants formulated for Electrolytes
are not regulated. Sugar before, during, Sugar
They can contain Water and after exercise. Water
200 milligrams or However, other than
more of caffeine Effects and drawbacks endurance athletes, Claimed benefits
per serving (a very Simple sugars can give an people are unlikely Formulated to replace
strong cup of coffee immediate surge in blood to run low on electrolytes lost in sweat,
might contain 180 sugar levels and caffeine can electrolytes or and replenish energy stores
milligrams), and may mask feelings of fatigue, but exhaust energy depleted by long exercise,
contain as many as any energy-boosting effects stores, so sports sports drinks are supposed to
400 calories. are short-lived and typically drinks rarely improve stamina and prevent
precede a crash. Negative perform better athletes from exhausting
impacts include weight gain, than water. their carbohydrate-based
headaches, and anxiety.
energy stores.

162 163DRINKS

Energy drinks

Stimulating the body CAFFEINE AND SPORTS

Energy drinks often contain Guarana Caffeine can increase Brain
caffeine, taurine, guarana, Seeds of the guarana muscle endurance and Heart
ephedrine (restricted in some plant contain more speeds up the production
countries), or ginseng—all caffeine than coffee of glycogen—the body’s Muscle
included as stimulants. Caffeine beans, but supposedly carbohydrate energy
works by stimulating adrenaline release it more slowly. store. High adrenaline
release and by blocking the They also contain cardiac levels boost blood flow
“fatigue” signal produced by stimulants theobromine to the heart and muscles
adenosine—a chemical made and theophylline. and stimulate energy
when the body's metabolism production. Adrenaline
releases energy. Ephedrine is may also reduce
also a stimulant but one with perceived levels of
dangerous side-effects including pain and fatigue.
high blood pressure and
heartbeat irregularities.

Do they work? PROTEIN SHAKE Conclusion ENERGY GEL
Designed to help As with sports
build muscle mass, Main ingredients: drinks, gels are Main ingredients:
protein shakes Protein powder unlikely to benefit Electrolytes
provide the amino Flavorings anyone other than Amino acids
acids necessary to Sweeteners endurance athletes, Additives
build up muscles. such as marathon
In reality, only What is on offer runners. For Product breakdown
high-level body- Protein shakes are drinks everyone else, they Highly concentrated into
builders need more made from protein-rich provide empty syrupy gels, these provide
than can easily be supplements, most often calories, with portable forms of energy
obtained in the diet. from whey (milk proteins left implications for supplement, intended for
Excessive levels of behind by cheese making), weight gain and endurance athletes on the go
protein may cause but also from casein in milk, diabetes risk. who need to minimize the
kidney damage and soy, egg, hemp, rice, and pea. weight they are carrying. They
bone loss. They are high in calories. may also contain caffeine

and other stimulants.

Alcohol IS ALCOHOL
A POISON?
All alcoholic drinks contain ethanol—the chemical
name for the simplest form of alcohol. Most forms In sufficient amounts, alcohol
of alcohol are made by fermenting grains (for beer, see slows down brain function,
pp.172–73) or grapes (for wine, see pp.170–71). More irritates the stomach,
pure forms of alcohol are produced by distillation. dehydrates you, and lowers
your body temperature and
blood sugar levels. So yes,
it is a poison.

2 Evaporating alcohol 3 Condensing
Ethanol boils at 173ºF In the pot
distillation process, the
Volatile compounds (78.4ºC) so it evaporates, different components
such as ethanol leaving water behind. Other
evaporate chemicals in the mix, including condense as the evaporate
passes through a system
highly toxic methanol, are also of cooling pipes.
volatile so evaporate, too.

BOILER

Cooling pipe

CONDENSER

Distillation Distillate collects

Alcohol is made initially through the 4 Distillate Methanol
fermentation of sugary plant juices. The distiller This lightest of alcohols
Distillation is used to produce a more must draw off and comes off first. Distillers
pure form of alcohol. The various discard lighter volatile throw this away because
components of a mixture boil at different compounds (congeners), it is poisonous.
temperatures, so as the mix is heated, which pass through Ethanol
some components boil off before others. the condenser first. In The principle alcohol
If these can be captured and condensed small quantities, these in all alcoholic drinks.
separately, it is possible to obtain alcohol congeners provide flavor.
of 95–98 percent purity. Butanol
This gives some spirits
The distillate is diluted their oily nature, as its
for consumption (see structure is similar to
pp.166–67). those of fatty acids.

1 Heating the ferment COLLECTING VESSEL
Grapes (to produce brandy, for example) or grain (to
make whiskey) are first fermented to produce alcohol.
Once the fermentation has finished, the ferment is heated
inside the distillation plant or still.

164 165DRINKS
Alcohol

How much in a drink? Calorie count
At 7 calories per gram, alcohol contains almost as many
Guidelines as to what counts as moderate calories as pure fat. Most drinks contain sugars, too, which
drinking, and particularly what constitutes add to the calorie count. The drinks below each contain
a standard drink, vary by country. In the US, 0.6fl oz (14g) alcohol—a standard US drink.
one standard drink contains 0.6fl oz (14g) of
alcohol, while in Austria it is 0.3fl oz (6g) and PURE 5fl oz (150ml)
in Japan 0.85fl oz (19.75g). In the UK, official ALCOHOL 12% alcohol
guidelines refer to units (one unit is about 125 calories
0.35fl oz, or 8g, of alcohol).

12fl oz (355ml) Many of the calories Red wine can be up
5% alcohol in beer come from to 16% alcohol, and
155 calories unfermented sugars even more calories

1.5fl oz (44ml) 6.5fl oz (192ml)
40% alcohol 5% alcohol
95 calories 150 calories

Alcohol and calorie
content depends
on the ratio of
alcohol to mixer

BEER SPIRITS WINE SPIRITS AND MIXER

Is alcohol ever healthy? RISK OF STROKE

There is a paradox around alcohol and health.
Alcohol increases the risk of liver disease and
a range of cancers, but studies have shown a
correlation between moderate alcohol consumption
and improved heart health. Some experts are
sceptical, others point to beneficial effects of
antioxidants or nitrous oxide boosting blood flow.
There may even be a link to less anxiety and more
sociability, with associated health benefits.

MODERATE ALCOHOL 012 3 4 5 67
INTAKE MAY REDUCE NUMBER OF DRINKS PER DAY
STROKE RISK
The case of stroke
Small amounts of alcohol may have a protective effect on
the heart. One study in 2007 showed how the risk of stroke
(purple line) correlated with alcohol intake—with a moderate
consumption having a protective effect. However, more
recently other studies have raised doubts over this.

Spirits

Ever since ancient and medieval pioneers first practiced the Distilled from a
art of distillation, the production of spirits has been an fermented mash of the
alchemical process capable of transforming base heart of agave plants (a
ingredients into concentrated alcohol. kind of cactus), which
are rich in fructose (fruit
Spirit or liqueur? Spirits distilled from grape sugar) and inulin. Inulin
wine. The two most famous is an indigestible chain
Spirits are alcohol (ethanol) products made of fructose sugars and
by the distillation of a fermented mash brandies—Cognac and
(see p.164). While beer may contain as Armagnac, named after their is broken down by
little as 3 percent alcohol by volume (ABV), French regions of origin—are steaming or roasting
spirits have an alcohol content of more
than 20 percent and are generally at least made from white wine. the agave hearts.
40 percent. A liqueur is a sweetened, and
often flavored, spirit.

Popular spirits Blue agave
Spirits differ according to the source of their original is the species
fermented sugars, as well as by the purity of the commonly used
distillate before it is diluted. Coloured impurities
in the distillate (congeners) provide flavor. in tequila

ALCOHOL IS THE CAUSE Fermented
OF 5 PERCENT OF ALL grape juice
CANCERS WORLDWIDE yields brandy
when distilled
BRANDY TEQUILA

Drinking dangers One extra
case
Although some data suggests one
or two drinks a day can benefit NO ALCOHOL 10.5 UNITS PER WEEK ARE SPIRITS MORE
heart health (see p.165), even HARMFUL THAN WINE
moderate drinking could be a cause 22 UNITS PER WEEK Three extra
of cancer. Alcohol has been linked lifetime cases OR BEER?
with nine cancers, including mouth per 1,000
and throat, liver, breast, and bowel. people All forms of alcohol are
The chief suspect is acetaldehyde, harmful, being broken down
a breakdown product of alcohol. Eleven extra into toxic substances in the
cases per 1,000 liver. Spirits are more strongly
Mouth cancer
Oral cancer cases increase with alcohol linked with mouth cancer,
consumption (1 unit = 1/3fl oz, or 10ml, of pure especially in smokers.
alcohol, or one modest drink). When it comes
to cancer, there is no safe drinking limit. 44 UNITS PER WEEK

166 167DRINKS
Spirits

Traditionally made Whiskey is essentially Originating
from the cheapest made from beer, in by-products of
the sugar industry
starch source without the hops, since in the Caribbean,
available, vodka is it is distilled from rums are distilled
usually made from fermented grain— from fermented
grain but also from molasses. Light rum
mainly barley, corn, rye, is distilled to a high
potatoes and or wheat. Barrel-aging purity, but dark
sugarbeet. The source rums retain more
contributes to the
is less important character of the flavorful
because the spirit is finished drink. congeners.
distilled to great purity,

excluding most
aromatics.

Some traditional Malted barley (barley Sugarcane juice
vodkas are still that has sprouted and is the source of
made from begun releasing its molasses for rum
fermented potatoes sugar—maltose) is
the starting point
Most vodka is for many whiskeys
made from grain

VODKA WHISKEY RUM

Alcohol abuse EXPLOITING DENSITY

Alcohol and its breakdown products CIRRHOTIC The strongest, most COINTREAU
(such as acetaldehyde) are toxic LIVER alcoholic drinks float IRISH CREAM
to many different organs and on water, since water
tissues of the body. Long-term Lumps of fibrous is denser than ethanol. LIQUEUR
overuse of alcohol over a decade scar tissue Heavier ingredients, COFFEE
or more can damage most however, such as coffee, LIQUEUR
systems of the body and seriously Liver damage make most drinks
increase the risk of cancer (see Alcoholic cirrhosis of the liver heavier than water. B-52 SHOT
opposite), liver disease, stroke, is where alcohol breakdown Skilled bartenders
heart disease, brain damage, products damage the liver, exploit different drink
neurological damage, depression, causing it to regrow with scar densities to create
seizures, gout, pancreatitis, and tissue and fatty deposits that layered cocktails.
anemia. In all, over 60 diseases limit its ability to function.
have been linked to alcohol abuse. Cirrhosis can be fatal.

Alcohol and the body

Alcohol gets into the body very fast. Unlike Genes and alcohol
most food and drink, it is absorbed into the
bloodstream within minutes. It takes the liver Some ethnic groups have genetic
about one hour to process one unit of alcohol, variations that prolong the endurance
forming a highly toxic compound as it breaks of acetaldehyde in the body. This can
it down for elimination. cause unpleasant nausea and flushing,
but may also have the effect of putting
Effects of alcohol on the body them off drinking. Genetics can also
play a part in whether someone is
As alcohol hits the stomach, around 20 percent begins to cross predisposed to become an alcoholic.
into the bloodstream right away. It is quickly passed to the
liver, brain, and pancreas, where it starts to break down. The Red flush
rest is absorbed through the gut. Alcohol is first broken down
into acetaldehyde, then acetate, and is finally eliminated as
carbon dioxide and water. Acetaldehyde is highly toxic and
causes damage to cells, especially those of the liver, which
can become irreparably damaged.

MOUTH STOMACH CIRCULATORY SYSTEM LIVER
Warm feelings Fatty liver
Taking it in Upset stomach Alcohol makes the blood vessels Repeated use leads to
Contact with strong alcohol Alcohol stimulates the stomach widen, making you feel warm. It inflammation and scarring of
can damage the cells lining the to produce large quantities of also causes a temporary drop in liver cells. Fat becomes deposited
mouth, throat, and esophagus, acid that can irritate the lining blood pressure and pulse rate. between the cells, making it hard
promoting cancers in these areas, of the stomach and lead to Small vessels can also break. for the liver to work properly.
especially among smokers. ulcers over time.

Under the influence IT TAKES ABOUT THREE
Alcohol is a psychoactive drug. HOURS FOR YOUR BODY
In small doses it acts as a depressant, TO BREAK DOWN THE
but reduces inhibitions and anxiety ALCOHOL IN A LARGE
to produce feelings of euphoria. (8.5 FL OZ/250 ML)
At higher doses it causes intoxication, GLASS OF WINE
stupor, and unconsciousness.

168 169DRINKS

Alcohol and the body

0.03g/mL BLOOD 0.08g/mL BLOOD 0.2g/mL BLOOD 0.3+g/mL BLOOD Alcohol—the backlash
Mood picks up, Judgment, vision, Loss of motor Acute risk of
balance, and speech Hangovers only start after
inhibitions disappear, start to be affected control and mental alcohol poisoning
feel euphoric function and death all the alcohol has been

metabolized. Typical symptoms

include tiredness, dizzyness,

nausea, and headache and can

last for 24 hours. Dehydration is

0 0.1 0.2 0.3 often blamed for the HIGH
effects, but the real
Hand-eye
coordination culprits are thought
affected
to be congeners— BRANDY
by-products of

fermention that

0.12g/mL BLOOD 0.3g/mL BLOOD often give the drink RED WINE
Bodily coordination May become unconscious—
and judgment impaired its flavor and color. HANGOVER SEVERITY
hospitalization required
Some experts also RUM

propose a theory

Blood alcohol levels that hangovers may WHISKEY
As you drink, the concentration of alcohol in
your blood rises. This leads to an increasing loss be due to reactions
of control of physical and mental faculties.
of the immune WHITE WINE

system. GIN

VODKA

BEER

LOW

KIDNEYS BRAIN LUNGS
Dehydration Off your head
Alcohol increases urine Some alcohol is broken down Breathing risks
production as soon as 20 by the brain, which is instantly Drinking increases the risk of
minutes after being drunk. affected. Control of mental and inhaling vomit and also affects
Excess drinking can lead to physical functions becomes nitric oxide levels, both of which
thirst and dehydration. progressively harder. make the lungs more susceptible
to infection.
WHY DOES

CHAMPAGNE MAKE

Alcoholism YOU DRUNK SO FAST?
Overuse of alcohol can tip a
social drinker into becoming The bubbles in champagne
an alcoholic. The body helps the body absorb alcohol
develops a physical tolerance
to alcohol and it becomes into the bloodstream more
psychologically difficult to quickly, as do carbonated
stop drinking. Giving up
produces withdrawal mixers with spirits.
symptoms that can be as
bad as those of drinking.

CRUSHER Fermentation vessel is warm, CHEMICALS IN WINE
RED encouraging the release of
GRAPES chemicals from the skins Procyanidins
and seeds A kind of tannin that makes young reds
bitter, procyanidins may act on artery
1 Grapes linings to improve cardiovascular health.
crushed
To release juice, Resveratrol
grapes are first FERMENTING Warm fermentation This phytochemical has been shown in
crushed and the TANK 2 Yeast ferments the crushed rodents to lower blood sugar and fight
cancer (in high doses).
stems removed. grapes, converting its sugar to
alcohol. Winemakers may add a Flavonols
The squashed cultured yeast, or they may rely Shown to have antioxidant and anti-
grapes, with cancer actions in animals, although
skins and seeds, on the yeast on the grape skins. the dose in red wine is very low.

are poured out. PRESS Anthocyanins
The human body metabolizes these
antioxidants quickly, so if active, they
must be effective in trace amounts.

3 Pulp pressed Richly colored press wine pours
The crushed, fermented grapes from the press and is added to
flow into the wine press, which applies the free-run juice to improve
appearance and flavor

pressure to release further color
and flavor from the grapes.

Wine from the fermenting tank, known as free-run Secret ingredients
juice, is mixed with a little fluid from the press The red wine making process fills
your glass with extracts of grape
Is red wine better for you? skins and seeds. It is not clear
which of these, if any, benefits
Interest in the possible health benefits of moderate wine drinking human health. One chemical
reached a high in the 1990s. It was then that US journalists noted that called resveratrol has a range
the population of France was longer lived and more free of coronary heart of benefits in lab mice, but only
disease than those of other countries with high-fat diets, such as the UK in doses impossible to achieve
and US. Attention focused on red wine, because unlike white, it is made by by drinking wine. Procyanidins
fermenting whole grapes, skins and all, and contains a range of chemicals in high-tannin wines might be
such as tannins, flavonoids, and pigments called anthocyanins. Scientists more promising candidates.
are still investigating the therapeutic actions of many of these.

Wine

In recent decades, wine has gained publicity for its
potential benefits to health. Some experts claim a
glass of red a day lowers the risk of heart disease
and other cardiovascular problems. So what is it
about wine that is healthy, and is red better?

CRUSHER

WHY NOT Pulp contains RED OR
JUST EAT GRAPES? juice, skins, WHITE GRAPES
and seeds
The supposedly beneficial 1 Grapes are crushed
ingredients in red wine are also FERMENTING The white wine
present in the skins and seeds of TANK process begins with crushing
PRESS grapes to release the juice.
the grapes we eat. However,
many people prefer to 2 Grape pulp pressed
eat seedless grapes, or The press separates
avoid chewing the
bitter seeds.

the skins and seeds, which
are discarded. Clear, filtered
juice runs out of the press.

Pure fermented 3 Cold fermentation Tannins and
juice (white wine) The pure grape juice is cold-fermented antioxidants are
filtered out with
by yeast in vats or sealed barrels. The process the seeds and
gives a fresh, juicy taste, without the bitterness skins before
or astringency of tannins. fermentation

WINE IS AN INGREDIENT IN THE
OLDEST KNOWN RECIPES FOR
MEDICINE, DOCUMENTED IN
2200 bce, ON PAPYRI IN EGYPT

IT’S ONLY A GLASS

A little of what you like Wine measures vary from place to 125
In white wine, the skins and seeds calories
are removed before fermentation so place and according to trends, so it
white lacks the phytochemicals of 200
red wine. However, experts are can be difficult to know that you calories
learning that the health benefits of
red wine may have been overstated, drinking in moderation. A large glass 600
and some studies find, paradoxically, calories
that it is actually the alcohol in can be one-third of a 750ml (25fl oz)
wine that is healthy (see pp.166–67).
If true, white-wine drinkers could bottle, containing 200 calories,
also benefit from a glass a day.
or more, in the form of sugar and

alcohol. Alcohol content has increased

in recent years, as modern production

involves leaving fruit to ripen longer

on the vine, so it becomes more

sugary, resulting in more alcoholic 150 ml 250 ml 750 ml
wine with more calories. (5 fl oz) (8.5 fl oz) (25 fl oz)

Beer WHY IS BEER SOLD
IN TINTED BOTTLES?
Probably the first alcoholic drink created by
humans, beer is the world’s most widely produced Dark or tinted glass blocks
and consumed alcoholic beverage. This is reflected the ultraviolet light that would
in the enormous variety of beers now available.
otherwise cause the beer to
Brewing spoil. This process is known

Brewing relies on mobilizing the sugars in grain. This is usually begun as “skunking” or being
by malting—letting the grain sprout, so that it converts its stored starch “light struck.”
to the sugar, maltose. Brewers add flavors to the ground grain, such as
hops (a flower that imparts bitter or zesty tastes), and the brew is then
fermented with yeast. The finished beer can be left with some yeast to
continue to mature in a cask, or it is stored, yeast-free, in bottles or kegs.

1 Producing the mash 2 Lautering 3 Boiling
Milled, malted grain and The initial extraction fluid— The wort is boiled for up to
hot water are mixed to produce wort—is drawn off, and then the solid
the mash. Enzymes in the grain remains of the malt are sparged, or two hours to deactivate enzymes,
and to bring out bitterness. Hops
convert its starches into sugar. washed, to release remaining sugars. are added at this stage.

6 Conditioning 5 Fermenting 4 Centrifuging
The beer is matured with a Yeast is added to the wort and The wort is cooled in a
heat exchanger and then put in a
second fermentation to develop the mixture is fermented for four to five centrifuge to remove coagulated
flavor and carbonation, and
cleared of detritus before packaging. days, during which sugars are converted proteins and spent hops.
to alcohol and carbon dioxide.

IN 2014, BEER BELLY
9.25 GALLONS
(35 LITERS) Although beer contains antioxidants,
OF BEER WERE B vitamins, and minerals, it is also
PRODUCED FOR high in calories due to sugar and
EVERY ADULT alcohol content, and is often
ON EARTH consumed with fatty foods,
leading to weight gain.

Main beer varieties 172 173DRINKS
The two basic Western types of beer are ales, made using yeasts that Beer
ferment at the top of the brew, and lagers, fermented at the bottom. Top
fermentation is quicker and results in more color, flavor, and fruitiness. Types of beer

Light lager Beer has been around so long
Light lager is brewed using less malt, but that many different types and
by converting more of the sugar from methods have evolved around
which it is fermented, to give a beer with the world. Brewers often use
about the same alcohol content, fewer the main staple crops available,
calories, but less body and flavor. so while European and North
Lager American beers are made from
Bottom fermented in cold conditions, barley or wheat, many people in
originally in casks stored away in cool Africa and Asia brew their beer
cellars (“lager” is German for “storing”), from millet, sorghum, or rice. In
lager is a clean, crisp tasting beer with some parts of South America and
about four to five percent alcohol. Africa, when making beers from
Wheat beer corn or cassava root, some beer
Often known as white beer, these makers aid the brewing process
top-fermented beers use a high with their own saliva enzymes,
proportion of wheat compared contributed by chewing the crop.
to barley, and tend to be foamier,
hazier, tart, and fruity. GETTING A HEAD
Ale
Top fermented, with a robust, hoppy, A head of foam helps to release
fruity character, ales are more colorful a beer’s aroma and flavor. Beer
and cloudy than lager. Although they develops foam because it is
taste stronger, they generally have carbonated and relatively high in
similar alcohol content to lager. proteins, which prevent the air
Stout bubbles from popping. Generating
Stout is a type of ale, in which unmalted and retaining the foam depends on
barley is sometimes used to create more variables such as the acidity and
browning and rich flavors. Noted for its alcohol content of the beer, and
dark color and for retaining its head, stout even the type of glass used.
has three to six percent alcohol.
Large Reduced
beer head beer head

Large
immobile
bubbles

Small
mobile
bubbles

HYDROPHILIC HYDROPHOBIC
GLASS GLASS



DIETS

Balanced diet Beans, pulses, and
fish are suggested
sources of protein

We all know that we should eat a healthy,

balanced diet, but what exactly does OIL DAIRY

that mean? It turns out guidelines GRAINS,
differ around the world. CEREALS,
TUBERS,
Government guidelines AND BEANS

Many countries’ governments provide nutritional

guidelines to help their people make good food PROTEIN

choices. These are based on scientific research

but are adapted to create an achievable diet in

each country. After all, there would be little

point recommending a diet so wildly different

from the national average that nobody even

tries to stick to it. While most

countries recommend a diet based United Kingdom FRUIT AND
on whole grains and plenty of fruit Starchy carbohydrates VEGETABLES
and vegetables, with limited sugar, and fruit and vegetables
salt, and fat, guidelines differ from should make up the bulk Five portions of
country to country. Some give more of meals, along with smaller fruit and vegetables
precise suggestions than others amounts of proteins and dairy a day are advised
for the different sources of protein, foods. The lack of sugary foods
and the proportions of dairy foods implies they have no place
in a healthy diet.

suggested vary dramatically. Sugar and oils are SUGAR OIL
suggested when
US GUIDELINES ADVISE
there is a shortfall
in calories

LESS THAN 10 TEASPOONS DAIRY
OF SUGAR A DAY,
NOT THE CURRENT
AVERAGE OF 22 GRAINS, CEREALS,
TUBERS, AND
OTHER BEANS

Water intake FRUIT BEANS/
The UK recommends India PULSES
Indian guidelines
6–8 drinks per day. suggest a diet rich in MEAT/
Water, tea, coffee, grains, dairy foods, and FISH
milk, and sugar-free vegetables. Much of
soft drinks all count. the protein comes from VEGETABLES
Fruit juice’s high sugar pulses, with a smaller
content means only amount coming from Homegrown or
one small glass should meat. Variety is important locally sourced
be consumed daily. in the Indian diet. vegetables are
recommended

176 177DIETS

Balanced diet

Soy-based foods
are recommended

GRAINS, OIL WHO ARE
CEREALS, DAIRY GUIDELINES FOR?
TUBERS
LEGUMES/NUTS Other than the very young,
FISH/SHRIMP the proportions of foods to be
eaten apply to everyone, but
MEAT/POULTRY
the total number of calories
consumed should vary

depending on age, gender,
and activity level.

FRUIT EGGS Guidelines
VEGETABLES aim to cut meat
consumption
by half

China GRAPHIC GUIDELINES
The focus of the
guidelines given to Many countries use a pyramid
the Chinese people is on to relate the recommended
cereals and vegetables, dairy proportions of the main food
foods, and smaller amounts groups. Others, such as South
of protein. Recommendations Korea and Japan, incorporate a
on avoiding food waste are reminder that physical activity is a
also included. necessary complement to eating well.

GRAINS, CEREALS, OIL The US- JAPANESE
TUBERS, AND DAIRY recommended SPINNING
OTHER BEANS diet includes a
relatively large TOP
FRUIT proportion of
dairy foods

VEGETABLES PROTEIN United States KOREAN
Americans are BICYCLE
Legumes, dark-green, red encouraged to focus
and orange, and starchy on the variety and AUSTRALIAN PYRAMID
nutrient density of their
vegetables are encouraged food, and to eat fewer
high-calorie foods with low
nutritional value. They
should limit saturated fats,
trans fats, sugar, and salt.

Do we need
YES supplements?

Many experts argue that Many people take multivitamins or other

supplements are beneficial, at least supplements as part of their daily routine,
for some people, and even if you aren’t but do we really need them? Health
in one of the groups that will benefit, experts disagree.
taking them won’t do you any harm.

They can be thought of as a “safety Vitamin D
net,” ensuring good nutrition.

Vitamin D helps our bodies to absorb calcium, and

No harm is a key factor in bone health. While we receive a
There is no evidence that taking small amount of vitamin D from the food we eat,
multivitamin supplements causes harm, most is made in our skin when it is exposed to
as long as they don’t provide significantly ultraviolet (UV) radiation in sunlight. However, not
more than the recommended intake of everyone can get enough sunlight, and many people
each nutrient.

at higher latitudes may benefit from supplements.

Benefits to specific groups 5–7 minutes 5–7 mins
Certain groups have been found 10 mins
to benefit from particular vitamin 30
supplements—particularly A, C, and D mins
in children, and folic acid in pregnant
women. These effects don’t show up
in large population studies.

Acts as a backup SUMMER WINTER
Even healthy diets can lack one nutrient or Vitamin D production
another occasionally. Vitamin supplements How much vitamin D the KEY
may act as a “safety net,” preventing accidental body makes can vary with age, Sun exposure time
deficiency. People who take them do show weight, and skin type (darker necessary for daily
fewer nutritional inadequacies, but this may skin requires more sunlight), vitamin D dose.
be because they also tend to eat healthily. as well as levels of UV exposure.
Boosts a poor or restricted diet The amount of sunlight our skin Tropical
Many people have a limited or poor receives is affected by our
diet, whether because of beliefs, latitude and the seasons. Temperate
illness, access to food, or simply being
fussy eaters. In these cases, a IS NATURAL
multivitamin can help to ensure ALWAYS GOOD?
adequate intake of vital compounds.
Can be tailored to specific needs Not all “natural” products
Males, females, and people of different ages are safe and beneficial. Many
and activity levels have different nutritional herbal supplements, and even
needs. Tailored supplements are matched
to the requirements of the group to which vitamins, can produce
you belong. This may be easier than dietary unpleasant side effects or
changes to ensure complete nutrition. interact with prescribed

medications.

178 179DIETS

Do we need supplements?

Multivitamins NO

Supplements offering multiple nutrients range from minimal to Many experts aren’t convinced
comprehensive. Many contain far more than the recommended that supplements are a good idea
dose of some vitamins, while they miss out others. Sometimes for everyone. They point to the lack
vitamins aren’t absorbed or processed as effectively when of evidence for their benefit in most
they are not taken in combination with the foods
in which they naturally occur. people, the possibility of harm
from high-dose formulas, and
TABLET WITH 24
INGREDIENTS their expense.

VVVVVVViiiiiittttttiaaaaaatammmmmmmiiiiiinnnnnninBBBBBBA765132 No benefits in general population
Large studies of healthy people have
V1Vi1VtVVViatmiiiiamttttaamaianimmmmnieniiirBinnnnaB1lDKC29Es
not found consistent evidence that
multivitamins are beneficial. Specifically,
they have been found to have no effect
on cardiovascular disease in the general
population, or on memory in older adults.

70 PERCENT OF PATIENTS Harmful
WHO USE SUPPLEMENTS Some multivitamins contain huge doses
OR OTHER ALTERNATIVE of each vitamin, which may be harmful.
THERAPIES DO For example, excess iron, selenium, and
NOT TELL
THEIR DOCTOR vitamin A can be toxic, so it is good
practice to keep all supplements out

of sight and reach of children.
Overdoses cannot be processed
If you take large doses of a vitamin or mineral,
even if it is harmless, if the amount is more
than the body needs, the body will treat it as
waste and excrete it. Water-soluble vitamins

cannot be stored for later use.

FOLIC ACID Not tightly regulated
Many vitamins are regulated as foods or
Folic acid, also known as vitamin B9, supplements, not drugs. So while safety must
is found in pulses, dark-green leafy be proven, composition and quality can vary
vegetables, and citrus fruits. Pregnant
women are advised to take lots of dramatically. Also, there is often
folic acid, as it helps to reduce the no guarantee you are getting
risk of spina bifida (defects in the exactly what’s on the label.
spinal cord and vertebral column) in Expensive
babies. However, as getting enough
folic acid from even the healthiest Multivitamins can be expensive, and in
diet may be difficult, supplements many cases the money might be better
are recommended for all women
in the early stages of pregnancy spent on supplementing the diet with
and even those trying to conceive. more fresh fruit and vegetables, which

also contain beneficial fiber.

Eating patterns DO NIGHTSHIFTS
AFFECT NUTRITION?
There is no scientific basis for recommending the
three-meals-a-day pattern that is common in so Shift workers are at higher risk
much of the world. Scientists are trying to discover of obesity, type 2 diabetes, and
whether eating differently could make us healthier. other illnesses. This may be due

Breakfast like a king? to reduced sleep leading to
higher calorie intake, or time-
Breakfast is often described as the most
shifted activities directly
important meal of the day, but is it? People who affecting the body’s
daily rhythm.
eat breakfast do tend to have lower BMIs (that is,
Large breakfast
they have lower body fat—see p.190), and Eating a large breakfast may
help you resist snacking before
those who skip it tend to have a higher lunch, but it isn’t clear whether
this will help you consume
risk of obesity, heart disease, and fewer calories overall.

other related disorders, possibly

because of the extra unhealthy BREAKFAST

snacks consumed when hunger hits 8:00

midmorning. But recent studies

contradict this and suggest that 6:00 10:00 12:00
breakfast-skippers still eat fewer

calories overall and suffer no ill

effects. Skipping breakfast also

extends the fasting period, which

may be beneficial (see pp.200–01).

Light breakfast Snack
Having a small breakfast, or skipping it While it is easy to eat a
completely, extends the overnight fast, lot of unhealthy foods as
which may be beneficial. However, it snacks and then gain weight,
might also encourage you to make less there is no evidence that
healthy food choices when you do eat. healthy, portion-controlled
snacks are bad.

BREAKFAST SNACK

Snacking SPANISH RHYTHMS

It is difficult to establish whether eating In Spain and the Spanish-speaking Americas,
little and often between meals is better for
your health than restricting eating to set people follow a markedly different pattern from
mealtimes. What is certain is that snack
foods are often high in calories and low three meals a day. The midday meal is the largest,
in micronutrients. There are good snack
options, however—fruit and nuts but cena (dinner) is eaten so
contribute to a better diet.
late (sometimes midnight)
Raiding the fridge
Midnight fridge raids and other snacking habits that people eat extra
have grown, as traditional social eating customs
have become less common in many countries. small meals, such as

merienda, to bridge

the gap. Tapas can

also be eaten in the TAPAS
period before dinner.

180 181DIETS

Eating patterns

MORE THAN Dine like a pauper?
53 PERCENT OF
AMERICANS SKIP An old folk saying tells us to eat a light evening meal.
BREAKFAST AT LEAST ONCE A Eating certainly affects the body clock—a set of
processes occurring all over the body every 24 hours.
WEEK, AND 12 PERCENT Body-clock processes in the liver and fat cells may be
ALWAYS SKIP IT disrupted by eating late in the day and may compete
with the body’s master rhythm. This may explain why
meals at night paired with daytime sleep affect the
body’s control of blood pressure and sugar level.

LUNCH Large midday meal DINNER Light evening meal
There is some evidence that Studies in mice found that their
2:00 consuming more of your 6:00 control of blood sugar varies over
calories earlier in the day helps the day. This could mean that light
reduce feelings of hunger, meals are better when we are less
making weight loss easier. active later in the day.

4:00 8:00 10:00

Light lunch Large evening meal
Distracted eating, such as a Dinner times have shifted later as
desk lunch, may lead to weight working and living patterns have
gain. Not paying attention as changed. It seems this may be
you eat means you are likely damaging to health, confusing
to overeat, or snack later on. the body’s natural rhythms.

LUNCH DINNER

Weight-gaining regime 0 A.M. FOOD PRE :00 A.M. BIG ME
AL
While most of us strive to keep body
fat down, sumo competitors rely on a P
low center of gravity to win wrestling G
bouts, so their daily regime of eating 5:0
and activity is aimed specifically at 8:0
developing a bulky physique.
Wrestlers’ days start with training 11
done on an empty stomach, then 1
they sleep at midday after an 0 A.M. TRAININ Sumo rules 2 P.M. LONG NAP
enormous meal. Scientists can’t Sumo competitors belong to
confirm why, but the sumo regime “stables” where their eating
does succeed in causing weight gain. patterns are strictly controlled.
They prepare their own hearty,

protein-rich stew called
chakonabe and eat it with huge

quantities of rice. A long nap
after lunch aims to encourage
the body to store calories as fat.

Western diets One plate each
Portions are
The term “Western” diet has come to mean served at the
the processed-food-dominated diet that is now start of the meal,
common across the world, but that originated and it is often
in the US and Europe. considered rude
not to finish the plate
Western customs of food. This can make it
difficult to respond to the
At most Western meals, each person is served a plate of food, body’s fullness cues as the
which they are expected to clear. Meals are based around protein
(usually meat), with accompaniments of vegetables and meal progresses.
carbohydrates. The main course is often followed by a sweet WATER
dessert, and sugary drinks are often consumed. Recently, trends
have moved away from shared family meals to snacks and
preprepared foods eaten on the go or in front of the television.

Western pattern diet

The modern Western diet is high in saturated fat, salt, sugar,
and omega-6 fats (see p.136), and low in omega-3 and fiber. It has
been linked to increased rates of obesity, heart disease, type 2
diabetes, and colon cancer. Some studies also suggest that it
might contribute to other cancers, inflammatory diseases such
as asthma and allergies, and autoimmune diseases.

HIGH WESTERN PATTERN DIET LOW

RED MEAT HIGH-FAT FRUIT VEGETABLES
DAIRY

PROCESSED SALT FISH LEGUMES OILS
FOOD

SUGARY SWEETENED LOW-FAT WHOLE Protein is main
DRINKS FOOD DAIRY GRAINS ingredient
The star of the
LOW WESTERN PRUDENT DIET HIGH meal is the protein:
usually meat or
Good versus bad diet sometimes fish.
Not every Westerner eats badly. The “prudent” diet includes less red Accompaniments
meat, processed foods, sugar, and salt, and focuses on whole grains, are chosen to
vegetables, fruit, and oils. Examples include the Mediterranean diet complement
(see opposite) and the vegetarian diet of the Seventh Day Adventists, its flavor.
which provide wide-ranging health benefits.

182 183DIETS

Western diets

Vegetables as Mediterranean food pyramid MEAT
accompaniments Mediterranean meals are based CHEESE
Vegetables are around whole grains, beans, YOGURT
often viewed as vegetables, and olive oil. Fish, fruit, WINE
a necessary but dairy foods, and wine are consumed
boring side dish to moderately, and meat and sugary FISH
the protein, and are dishes are considered FRUIT
served plainly boiled occasional treats.
or steamed. Different types
are usually cooked

separately.

WHOLE GRAINS
BEANS AND VEGETABLES

OLIVE OIL

BREAD SPOON The Mediterranean diet
FORK WINE GLASS
KNIFE The traditional diet followed by some people in
Staple is bread the Mediterranean region, and elsewhere, is
or potatoes Cold drink characterized by experts as “Mediterranean” and
Bread and The drinks served regarded as one of the world’s healthiest. Studies
potatoes are the with a meal are suggest that it lowers the risk of type 2 diabetes,
most traditional usually cold—wine, high blood pressure, heart disease, stroke, and
carbohydrates, water, carbonated soft Alzheimer’s disease. Olive oil consumption is key
although rice and pasta drinks, and juice are all in reducing inflammatory responses, reducing
are also common. These common. Sugary drinks blood cholesterol levels, and protecting the brain.
form an important part can add a lot of hidden
of the meal. calories to the meal. INUIT DIET

Traditional diets of the Inuit and other Arctic peoples

were rich in fish and sea mammals. However, since

there was very little opportunity to enrich the diet

with plant foods, it was one of the world’s most

restricted diets. Polar populations could survive

because eating organ

meat and chewing

whale skin provided SEAL

just enough vitamins.

NARWHAL

WORLD TYPE 2 DIABETES
CASES ARE PREDICTED
TO DOUBLE BY 2030

Eastern Vegetable dishes
diets Vegetables are
served as a dish in their
Eastern diets vary hugely, from own right, cooked and
the sushi of Japan to the curries seasoned with care and
of India. But they share a love of valued as a dish of equal
spices and strong flavors, and a status to those featuring
reduced focus on meat, compared fish or meat. They do not
to most Western cuisines.
simply accompany the
protein part of the meal.

Asian customs CHOPSTICKS

Despite their differences, Asian cuisines share clear RICE
similarities that make them distinct from Western cooking. DISH
One is the focus on vegetables as a main component of
a meal, rather than as an accompaniment. Another is the TEA
reliance on rice as the staple grain. The flavors and
ingredients are often chosen for balance, with pairings
between dissimilar flavors—sweet and sour, salty
and hot—more common than in Western cooking.

UNLIKE IN OTHER CULTURES, SHARED
THE CHINESE SERVE SOUP AT VEGETABLE
THE END OF A MEAL, AS IT IS
THOUGHT TO AID DIGESTION DISH

SOUP

IS GREEN TEA Hot drink
REALLY GOOD FOR ME? or broth
Fluids form an
At very high doses, important part
green tea’s active compound is of the meal, in the
antioxidant, anti-inflammatory, form of broth, soup, sauce, or tea.
and antimicrobial, and is thought Cold drinks are less common, in
to help regulate weight, burn some cases possibly due to an
Indian Ayurvedic teaching that
fat, and control blood cold drinks slow and dilute
sugar levels. digestive juices, although

science does not
support this.

Rice or noodles 184 185DIETS
Meals are usually
based around rice Eastern diets
or noodles, since rice
is easily grown OKINAWAN DIET
in most Asian
countries. White (or Many residents of the Japanese
polished) rice is favored, islands of Okinawa stay slim and
despite its lower nutritional healthy to the age of 100 or older.
value than brown rice, which Their low-calorie diet, high in fruit
has the husk left on. and vegetables (including their staple
purple sweet potato) and low in
refined grains, saturated fat, salt, and
sugar, is thought to be the reason,
along with an active, community-
based lifestyle.

SHARED VEGETABLE DISH PURPLE
SWEET
MAIN DISH POTATO
OR BOWL
POT OF TEA Higher risk group
SHARED FISH DISH
Some Asian ethnicities, including
south Asians, are more likely to
develop cardiovascular disease than
others, even when risk factors, such
as smoking and diet, are taken into
account. As Western food becomes
more popular in the East, and more
Asian people move to North America
and Europe, obesity and its related
problems are on the rise in these
high-risk populations.

Bowl filled It’s in the genes
repeatedly The incidence
It is common for of heart disease
individuals to take suggests people
food from shared from south Asia are
plates into their own more susceptible
bowl as many times as they like to the dangers of a
throughout the meal. In many Western diet. This
cultures, it is polite to leave some leads experts to
food, indicating that you have suspect something
eaten your fill and that in their DNA code
affects how they
the host has met respond to high-fat,
your needs. low-fiber food.

Religious and DO CHRISTIANS
ethical diets PERMIT ALL FOODS?

Many people, in all parts of the world, make diet No, some follow religious
choices based not just on taste and health, but on dietary laws, too. Mormonism
their ethical or religious beliefs. Whether we follow a prohibits alcohol and caffeine,
doctrine-defined set of laws, or a few self-imposed and during the 40 days of Lent,
guidelines, we each express our individual convictions
through the types of food and drink we consume. Christians deny themselves
luxury food or drink
as penance.

Religion-based diets Religion Permitted

Food and dining practices play an ISLAM Food conforming to Fish with fins and Chicken and other
important part in most religions, Muslim laws is called “halal,” scales; shrimp— birds (other than
both as expressions of religious meaning “allowed.” Animals according to birds of prey)
piety and group identity. While must be killed by a Muslim some authorities
religions share some similar using a single motion to the
practices, most have their own set JUDAISM throat with a very sharp Fish with fins Chicken and other
of laws that dictate what types of knife. Observers do not eat and scales birds (other than
food and drink they may, and may or drink in daylight during birds of prey)
not, consume. Guidelines for food the month of Ramadan.
preparation, including animal BUDDHISM Dairy foods
slaughter, are also followed. For “Kosher” foods conform to
some religions, particular days of HINDUISM Jewish dietary laws. Kosher Dairy foods
the week and times of the year also animals must be killed
have special dietary significance. using a single motion to
the throat with a very sharp
JAINISM knife. During the festival of
Passover, Jewish people
Jains follow an ancient Indian are forbidden from eating
religion with the principle of leavened (yeast-risen) bread.
nonviolence at its core. They go
out of their way to avoid harming Because of their belief in
any living creature and nonviolence, Buddhists are
eat a very strict often vegetarian or vegan,
lacto-vegetarian although this varies with
(egg-free) cultures. Some Buddhist
diet. They also monks beg for their food
exclude onions, and may eat meat if it is
garlic, and root given to them, as long as
vegetables that it was not killed for them.
are necessarily
killed when As Hinduism is aligned
harvested. with the concept of
nonviolence to all
beings, the Hindu diet
is mostly vegetarian.
However, many Hindus
do eat meat and animal
products, and regional
differences in diet exist.

186 187DIETS

Ethical and religious diets

Ethical diets Animal welfare Environment
Some people avoid People address issues
Our ethical beliefs can affect factory-farmed meat concerning land use
what foods we choose to eat or eggs, or other meat or and global warming
and how we source them. Most animal products that they by avoiding red meat,
vegetarians don’t eat meat consider to have been which does the most
because they believe killing produced inhumanely. environmental damage.
animals for food is unethical. Sustainability Waste
Similarly, many people express Avoiding some foods— People that have ethical
ethical concerns about issues such as types of fish— concerns about food
surrounding food production can slow the depletion of waste include so-called
when choosing food. these resources, allowing “freegans” who live
stocks to recover. off discarded food.
Permitted
Forbidden

Animals with cloven Permitted animals Animals not Pigs, shellfish, Blood Alcohol
hooves that chew slaughtered slaughtered fish without scales
the cud (cows, goats, according to according to
sheep, deer) halal principles halal principles

Animals with cloven Permitted animals Animals not Pigs, shellfish, Blood Wine or grape Meat and dairy
hooves that chew slaughtered slaughtered fish without scales products from products eaten
the cud (cows, goats, according to according to non-Jewish together
sheep, deer) kosher principles kosher principles producers

Vegetables, fruit, and Most animals Pungent foods with Alcohol
most plant-based foods strong flavors, such
as garlic and ginger

Vegetables, fruit, and Most animals Eggs Beef (extra Pork (extra
most plant-based foods prohibition even prohibition even
for meat eaters) for meat eaters)

Vegetarians P ROTEIN Eggs
and vegans
Dairy Nuts
Vegetarian and related diets are usually chosen Seeds
because of concerns over animal welfare,
the environmental impact of eating meat, Beans and pulses
or for their health benefits. Less strict
are pescatarians, who eat fish, and Vegetables
“flexitarians” who occasionally
include meat or fish in their diet.

Nutrients Leafy greens

It is possible to get all necessary nutrients from a IRON Eggs Seeds Fortified bread
wholefood vegetarian diet, but vegans will need to Dairy Nuts and cereals
consume some processed and fortified products
to get everything their body needs. The only reliable, Pulses
natural sources of vitamin B12, for example, are meat
and animal products, and there is very little vitamin D
in vegan products, other than fortified options.

Different varieties Grains

Vegetarians don’t eat meat or fish, but many eat Fortified salt
animal products such as eggs and dairy. In India,
eggs aren’t seen as vegetarian, but dairy foods are Nuts
encouraged. Vegans choose not to eat any products Seeds
that come from animals, including honey. Beans

FOOD TYPES VEGETARIAN VEGETARIAN VEGAN Dairy
(WESTERN) (INDIAN)
Eggs
Dairy IODINE Eggs
Honey
Vegetables Missing out
Grain A few nutrients need special attention
Fruit in a vegetarian diet. The forms of iron
Nuts and seeds and zinc found in plants are harder
Beans and pulses to absorb than those in meat, so more
must be consumed, and it is difficult
to get enough essential omega-3 fatty
acids without eating fish.

188 189DIETS

Vegetarians and vegans

ZINC ENVIRONMENT

Mushrooms Rearing livestock for food produces
Almond more greenhouse gas than all
forms of transport combined,
and uses huge amounts of
land and water. Switching
to a vegetarian diet can cut
a meat eater’s carbon
footprint by half.

Beans and pulses OMEGA-3 FATS 1lb (450g) of wheat 1lb (450g) of beef
Whole grains
Kale Walnut 25gal (95L) water 5,000gal (19,000L) water
Hemp seed
Supplements Health benefits
Linseed
Rapeseed Vegetarians have a reduced chance of obesity and
problems such as heart disease, high blood
Fortified foods, such Eggs VITAMIN B12 pressure, type 2 diabetes, and cancer. A healthy
as yeast extract Dairy vegetarian diet is lower in saturated fat and higher
Supplements in fiber, antioxidants, phytochemicals, and other
micronutrients. It also
Fortified influences the varieties
foods, such of bacteria that inhabit
as soy milk your gut.
Supplements
Vitamins

Spinach Minerals Microbes
Mushrooms Fiber Antioxidants
Sunlight
Vegetarian diets are high Fiber feeds the
Eggs VITAMIN D in many key vitamins good bacteria
and minerals
KEY Vegetarian options in your gut,
Vegan and vegetarian options 29 PERCENT which help keep
Fortified foods and OF INDIANS
supplements to a vegan diet ARE VEGETARIAN, your digestive
VERSUS 3 PERCENT system healthy
OF AMERICANS
LARGE
INTESTINE

FOOD Metabolism

Metabolism refers to our body’s vital
chemical processes, including extracting
energy from food and using it to build
molecules and repair our cells. Around
40–70 percent of the energy we burn each
day goes into these basic metabolic
functions—the proportion depends on
how physically active we are.

2 Build and repair
Amino acids circulate
through the bloodstream and
are used by cells throughout
the body to build proteins used
for growth and maintenance. Excess converted
3 to glucose

Any excess amino acids that
have not been used to make
INE INTERIOR proteins are converted by the
liver into glucose.
AMINO
INTEST ACIDS PROTEIN

AMINO ACIDS AMINO GLUCOSE
ACIDS

FATTY ACIDS GBLLUOCOODSEVIENSSAEL

FOOD

SUGARS

1 Food broken down 4 Main energy source
The body digests the food and drink Glucose travels in the blood
that we consume, breaking it down into
basic biochemical components or
building blocks: amino acids, fatty and provides body cells with a
ready source of energy. Any
acids, and sugars. that is not used is stored

as glycogen.

Energy budget YOUR BODY MASS INDEX
(BMI) IS SIMPLY YOUR
The way in which our body processes energy may WEIGHT IN KG DIVIDED
be understood in terms of an energy budget. How BY THE SQUARE OF YOUR
much energy we put in—through our food—and HEIGHT IN METERS
how much we expend—our levels of activity—
determine what we have left over—our fat stores.

190 191DIETS

Energy budget

BURNING FAT TO KEEP WARM Brown fat DOES HAVING A
used up in SLOW METABOLISM
Recently, scientists have discovered that reactions MAKE YOU PUT ON WEIGHT?
some adults have stores of brown fat that that create
burns to keep us warm. Previously, they heat No difference has been found
thought only babies had brown fat. They between the metabolisms of
have also discovered beige fat, which Regular overweight and slim people.
can change to an energy-burning state white fat If anything, metabolic rate
when the environment changes, such stores energy
as when the temperature drops. increases as your body
Finding ways to maintain this burnable size increases.
fat in the long term could lead to
treatments for obesity.

Losing weight GLUCOSE AND FATTY ACIDS
GLYCOGEN TO ENERGY
When we deprive it of food, our body TO ENERGY
exploits its stores of energy. First, it Fat burning AMINO ACIDS
uses all available glucose in the Glucose burning If the body does not have TO ENERGY
blood. Glucose is replenished as the If the body has a good enough glucose to burn, it
liver breaks down its glycogen store. supply of glucose, it will use will next turn to its fat Protein burning
When glycogen runs out, the body this as its primary source of stores for energy. When starved, the body
turns to its fat stores. So the only energy until it runs out. will take the extreme
way to lose weight is to remain in an measure of using amino
energy deficit—using more calories acids for energy.
than you take in—for a prolonged
period. Do this too strictly for long,
however, and muscles waste, as the
body breaks them down to liberate
amino acids for energy.

Putting on weight Glycogen Glycogen
store half full store full
When we consume more calories
than we expend through GLUCOSE GLUCOSE
metabolism and exercise, we store TO GLYCOGEN TO STORED FAT
the extra energy, first as glycogen, Storing carbohydrates Storing fat
then as fat. Fat is stored under the If we have a surplus of glucose that our When the liver reaches its full capacity for
skin (subcutaneous) and around our body has not used for energy, this is storing glycogen, any extra calories that are
organs in our abdominal cavity taken up by our liver cells and stored as a consumed are converted to fat and placed in
(visceral). It is visceral fat that leads complex carbohydrate called glycogen. stores throughout the body.
to obesity-related diseases. White
fat cells also secrete hormones and
hormonelike molecules, which
affect food intake (see pp.14–15)
and insulin secretion and
sensitivity (see pp. 216–17).

Diet and exercise

It’s commonly thought that exercise keeps HIGH-CAL ORIE DIET HIGH BMR
us slim, but recent research seems to be
casting doubt. While exercise is good for Fat/solid Large
you in many ways, an extra trip to the body shape amount
gym may not actually do that much of fat
for your waistline. Large muscles

Effects of exercise KEY

Exercise can help with weight loss,

and particularly weight maintenance, Calories

but it doesn’t have as large an effect Exercise

as might be expected. In the short

term, exercise seems to boost our XERCISE RCISE

basal metabolic rate (BMR—the amount of energy HIGH EXE

used daily at rest). It may do this by increasing High-calorie diet, high exercise
If you exercise a reasonable amount, you are likely
muscle mass, since muscle burns more calories at to have strong muscles and a high basal metabolic
rate. However, if you also eat a high-calorie diet
rest than fat does. However, new studies suggest you can still store fat and become overweight.

that once we reach a certain sustained high level

of exercise, our body may compensate by actually

reducing our basal metabolic rate.

High intensity exercise HIGH-CAL ORIE DIET Large
amount
High-intensity interval training (HIIT) seems to reduce Fat/flabby of fat
body fat more than other exercise, but why is not clear. body shape
One study found that for the same calories burned,
HIIT reduced nine times more subcutaneous fat than
regular exercise. Paradoxically, it also increased
fitness for both aerobic (sustained, low-intensity)
and anaerobic (high-intensity) exercise.

SPRINT CYCLE

Small muscles

Intensity LOW E

ENDURANCE CYCLE LOW BMR
High-calorie diet, low exercise
Time Taking in a lot more calories than you burn leads to
Peaks of intensity rapid weight gain and fat accumulation. If you don’t
HIIT involves working at full power for short periods—for take much exercise, you are likely to have undeveloped
example, cycling all-out for just 10 seconds, then resting muscles and a low basal metabolic rate.
before repeating the intense burst.

192 193DIETS

Diet and exercise

CALORIES BURNED

DIETLOW-CALORIE HIGH BMR It takes a lot of exercise 200 10 mins
RCISE Muscular to burn off even a few 120 Dancing
Small body calories. Walking at a 90 Cycling
amount shape moderate pace for 50 Walking
15 minutes, for example,
of fat Large muscles will burn off only the 200 calorie
equivalent of the calories granola bar
in a small apple. Because
of this, it can be fairly
difficult to create a calorie
deficit through increasing
levels of exercise alone.

HIGH EXE Gentle exercise improves mood ALZMHEOIOMDER’S
and seems to protect against STROKE
Low-calorie diet, high exercise Alzheimer’s disease
Reducing your overall calorie intake while increasing
your levels of exercise is the most effective way to People who are moderately active
lose weight. It will also help you preserve muscle are less likely to have a stroke
and change shape through depletion of fat stores.
Regular exercise helps to keep your SCLE
muscles strong and toned LUNGS
MU
Your heart becomes stronger and
more efficient with exercise

LOW-CALORIEDIET Small Regular exercise can help prevent the HEART
ERCISE amount buildup of fat in the liver LIVER
Thin of fat
body Weight-bearing exercise helps
shape build bone density in children;

Small in adults, it prevents it from
muscles being lost

LOW EX Wider health benefits

LOW BMR Even if it isn’t as useful for BONES
Low-calorie diet, low exercise weight loss as we once thought,
Someone who is relatively inactive can maintain a regular exercise offers a huge
healthy weight by eating a low-calorie diet. However, number of health benefits.
they will be missing out on the many health benefits It can lower your chance of
exercise offers. developing type 2 diabetes,
stroke, or heart attack, reduce
your blood pressure, and
improve your cholesterol levels,
independent of weight loss.

Calorie counting DOES LOW-FAT
MEAN LOW-CALORIE?
Counting the calories in the food we eat is a basic
strategy of weight management. While a “calorie- Low fat diets do tend to
controlled” diet may be a useful way to monitor our reduce calories overall, so
intake, we shouldn’t make food choices on calorie can work for weight loss. But
content alone. For optimum health, we must still many low-fat products have
eat a balanced diet containing all food groups. more sugar and salt added,
meaning they aren’t always
DENSITY
the healthier choice.

M DENSITY
HIGH
MEDIU

Energy-dense foods DOUGHNUT PEPPERONI PIZZA
Energy-dense foods typically contain 125kcal/ 74kcal/28g (1oz)
a high proportion of fat, and often 1oz (28g)
lots of sugar. They include baked Medium
foods made using butter POTATO CRISPS energy density
and oil, and many 157kcal/28g (1oz) These foods have a more
processed foods. balanced combination of
fats, carbohydrates, and
protein. Some fruits and
starchy vegetables could
also be included here.

CHOCOLATE CAKE
175kcal/28g (1oz)

Energy density SELF-IMPOSED RESTRAINT

The energy density of a food is the amount of energy A custom practiced by the people of Okinawa, Japan,
it contains per unit of weight—usually expressed in hara hachi bu roughly translates as “eat until you are 80
calories per gram (kcal/g). Energy-dense foods provide percent full.” The Okinawans are known for having the
more calories per gram than those with low energy world’s highest proportion of centenarians, and their
density. A food’s energy density is determined by its approach to eating clearly plays a role in this. Hara
proportions of fat, carbohydrates, protein, fiber, and hachi bu contrasts with the traditional Western custom
water. Fat contains 9kcal/g, carbohydrates and protein of eating until the plate is completely empty.
both contain 4kcal/g, and alcohol 7kcal/g. Fiber and
water provide no energy—just structure and bulk.

194 195DIETS

Calorie counting

What is a calorie? FOOD Measuring calories
SAMPLE A food’s calories are measured by
A food calorie is a unit used to measure the energy WATER burning a freeze-dried sample in
in food. Although the calorie is widely used in the oxygen. The calorific value is
context of food, scientists now mainly use the joule measured by how much a volume
as a unit of energy, and the kilojoule (kJ) for food of water, surrounding the food,
quantities. One food calorie (kcal) converts to increases in temperature.
4.184kJ. Depending on location, food labeling
uses either one or both of these units.

STEAK LOW DENSITY
50kcal/
28g (1oz) CARROTS BROCCOLI
27kcal/28g (1oz) 10kcal/28g (1oz)
LASAGNA Low energy density
46kcal/ Low in fat, but with a high BEETS
28g (1oz) percentage of fiber and water, these 12kcal/
foods include most vegetables and 28g (1oz)
legumes, and brown rice. Low
energy density foods tend to be TOMATOES
more bulky and filling. 5kcal/
28g (1oz)
BROWN RICE
28kcal/
28 (1oz)

VEGETABLE SOUP
17kcal/28g (1oz)

Absorbing calories Portion 45% 20% Varied absorption
passing 55%
Our bodies don’t treat all foods straight 80% Many of the plant cells that
equally. Some are harder to digest through RAW PEANUTS make up nuts aren’t broken
than others, which means we don’t the body down as they pass through
extract all the calories they contain. our gut, meaning their
Furthermore, we are not all same, Portion nutrients remain locked up
and one person’s digestive system absorbed inside the indigestible cell
may extract more calories than walls. However, in nut butter,
another’s from the same meal. the processing has started
the digestion process for you,
PEANUT BUTTER so you extract more calories.

Low-carb diets

Fat burning Proponents of “low-carb” diets claim that
By reducing the levels of glucose in limiting our consumption of carbohydrates can
our bloodstream, we can force our help us to lose weight and avoid the side effects
body into using alternative sources of eratically fluctuating blood-sugar levels.
of energy. A sustained lack of glucose
can lead to ketosis, a state in which How it works
the body burns its stores of fat at
a very high rate.

In low-carb diets, instead of carbohydrates providing the main

BRAIN C source of calories and energy, fats and proteins do. It is claimed
that by keeping our blood sugar and insulin levels low, we can
CELL train our body to burn its stores of fat. Also, since low-carb diets
ELL LIVER
are high in protein, and protein helps us to feel full for longer,

this enables us to eat smaller portions, reduce snacking between

meals, and cut down our overall calorie intake.

Ketone body What to eat? Egg-based meal BREA
being used for with a high
energy in a Anyone planning to significantly KFAST
brain cell proportion of
protein

reduce one of the main food groups

Ketone body needs a diet strategy that will OMELET SPINACH
produced from compensate. While protein-rich foods and
fatty acids in natural fats can replace carbohydrates as
the liver

sources of energy, high-protein diets often

lack fiber, which is essential for healthy

digestion and maintaining good cholesterol

levels. Including generous servings of

vegetables such as broccoli, cauliflower,

and lettuce in your diet can boost fiber Daily diet
By combining protein-rich foods with bulky
intake, contribute micronutrients, low-carb vegetables it is relatively easy to
eliminate carbohydrate-rich foods such as
Fatty acid and add bulk to meals. pasta, bread, rice, and sugary foods from
each meal of the day.
released into

bloodstream FAT

2 State of ketosis LOW-CARB DIETS CAN
Unlike other tissues,
the brain can’t use fatty
acids as an energy source. Stored fatty acid HELP PEOPLE WITH

So when blood glucose is Fatty acid being DIABETES IN THE
low, the liver converts fatty used for energy
acids into ketone bodies—
molecules that provide in muscle cell MUSCL SHORT-TERM
CONTROL OF
energy for brain cells.

1 Releasing fatty acids E CELL BLOOD-SUGAR
When blood glucose levels are LEVELS
maintained at a healthy level, insulin levels
remain low. This allows the release of fatty
acids from fat cells into the bloodstream,
which are then used for energy in most cells.

196 197DIETS

Low-carb diets

WHAT IS THE LIMITED FOODS BEET
CONSENSUS ON
LOW-CARB DIETS? Some low-carb diets are very restrictive, and as SQUASH
well as cutting out foods that are obviously rich
Although most medical in carbohydrates, such as pasta and bread, they DIN
organizations recognize the limit the intake of many other foods, at least at
effectiveness of low-carb diets first. These include all fruit and sweet-tasting CHICKEN
for weight loss, very few, if vegetables such as peas and corn. Potatoes BREAST
and other starchy vegetables including
any, recommend them as squash, carrots, parsnips, beets, and lentils BROCCOLI
a long-term health are restricted, as are whole grains including
strategy. quinoa and oats. However, many of these
foods are key sources of fiber, vitamins, and
LUN minerals, which are essential in a healthy diet.

SNA Dinner lacks
high-carb foods

such as pasta
and potatoes
NER
CK
CH

TUNA CHEESE

SALAD Low-calorie, NUTS High-protein, CAULIFLOWER
low-carb salad high-fat snacks are
makes up the eaten instead of
bulk of the meal wheat-based snacks

High-protein diets Benefits Drawbacks

Low-carb diets are, by MODERATE HIGH- • Protein helps you feel full for longer so you • Research is mixed as to whether these diets will help
definition, often also high- PROTEIN DIETS may be less likely to snack between meals you lose weight
protein diets. Moderate
high-protein diets • A high-protein diet during weight loss can • Protein-containing foods, including meats, are often
increase protein intake help you lose fat rather than muscle more expensive
above the standard
recommended amount— • Protein takes more energy to digest, so • Eating too much animal protein may increase your risk
around 15 percent of some of the calories will be burned off of developing heart disease and some cancers
total calories. They
continue to allow other EXTREME HIGH- • Protein keeps you full for longer so • A very restrictive diet is difficult to stick to, especially
food groups, including PROTEIN DIETS you are unlikely to become hungry when socializing
carbohydrates. More
extreme high-protein • Lots of popular foods, including meat, • Cutting out food groups can lead to a lack of
diets dramatically restrict cheese, and butter are unrestricted essential vitamins and minerals
carbohydrate intake.
Some also encourage • Many extreme diets don’t involve the • Lack of fiber can cause constipation
high fat intake. need to count calories
• Reliance on animal proteins may put you at risk of
diseases including heart disease and some cancers

• Cholesterol levels may increase

• Kidney problems can become worse as the kidneys
have to deal with more protein

• May be ineffective if calories aren’t restricted

High-fiber diet IS FOOD
WITH ADDED FIBER
Diets such as the F-Plan Diet became popular AS GOOD AS FOOD
in the 1980s after Dr. Denis Burkitt connected NATURALLY HIGH IN FIBER?
the benefits of traditional rural African diets
with their high fiber intake. The idea went out Producers may add fiber to
of fashion as the focus moved to reducing carbs, cereals, bread, yogurt, and other
but it is now becoming popular again. products. Although the fiber is

Benefits of a high-fiber diet less varied than natural fiber,
the beneficial health
As a weight-loss plan, high-fiber diets reduce calories while increasing effects are almost
fiber. The diet focuses on eating plenty of vegetables and whole grains, the same.
so it fits with governmental guidelines on healthy eating and is
recommended by many dieticians. No food is off limits, and the foods What to eat
eaten can reduce the risk of obesity, diabetes, and other diseases A high-fiber diet should contain lots of fruit
related to insulin resistance. However, some people find high-fiber and vegetables (including skins and peels, where
foods unappealing, which may make the diet difficult to stick to. If possible), whole grains, nuts, seeds, beans, and
water intake isn’t increased, it can cause short-term constipation. pulses. By swapping to items like whole-wheat
bread and high-fiber breakfast cereals, you can
easily increase your fiber intake.

BREA LUN Leave the skin on SNA
fruit to maximize
APPLE
fiber intake
CK
CH
KFAST

BRAN FLAKES WHOLE-WHEAT FIG
BANANA SANDWICH
DRIED
APRICOTS PRUNES

A banana contains Switch to PISTACHIOS
about 1/10oz (2–3g) whole-wheat
of fiber bread for
sandwiches

ONE STUDY FOUND HIGH-FIBER FOODS
THAT PEOPLE LOST
WEIGHT SIMPLY Well-known high-fiber foods range from 5 percent fiber
BY ADDING FIBER by weight (broccoli) to 15 percent (lentils) and also
TO THEIR DIETS, include whole-wheat pasta, avocados, and peas.
CHANGING Eclipsing all of these, however, are chia seeds,
NOTHING which are 37 percent fiber, four-fifths
ELSE! of which is soluble. That is why when
soaked in water, chia seeds dissolve
into a gloopy gel—a useful
consistency for desserts.

Chia seeds soaked
in water form a gel