Preventing Childhood Obesity - Evidence Policy and Practice.pdf

Chapter 14
Changes in the food
environment — the
nutrition transition
Beginning in the 1960s, the green revolution increased
the production of cereals, rice, wheat and maize —
staples for much of the world. As a consequence, three
major changes have occurred:
1. the relative price of food has declined, especially
for high calorie foods filled with fat and sugar;
2. food is increasingly easily accessible; and
3. multi-national corporations have invested heavily
in advertising and marketing to sell more of their
products, making cues to eat more salient.
Together, these three changes have made it possible
for people to eat as much as they can whenever they
want, as well as making people eat too much, and
artificially stimulating people to feel hungry when
they do not need to eat.
Food prices
The increasing yields and production of all staples
have led to lower food prices overall in relation to
income, 9 and in the United States, in 2006, the average
family spent only 9.9% of their income on food compared
to 14.8% 40 years earlier and nearly 25% in the
1920s. 10 Interventions that have manipulated the price
of food have shown that when healthier foods are less
11 – 13
expensive people are more likely to buy them.
Another study, examining the incidence of obesity
in elementary school children, showed that in communities
where the cost of meat was high and vegetables
were low, children were less likely to become
overweight than in communities where meat prices
were low and fruits and vegetables were high. 14 People
are sensitive to price, and when food is cheap, they are
able to purchase more. When high - calorie foods
are cheaper than lower - calorie foods, more people
purchase and eat too many calories. 15
Food accessibility and portion sizes
Another dramatic change in the food environment
has been the increase in portion sizes. Portions for
beverages in 6 oz and 8 oz sizes, for example, are no
longer sold in the US, in favor of 12 oz, 16 oz, 20 oz and
larger sizes. The typical American restaurant now
serves portions that are 2 – 5 times in excess of
what indi viduals typically require to stay in energy
balance.
16 – 18
Beyond portion sizes, the number of
places that now sell food has also increased dramatically.
While the number of convenience stores and
restaurants has increased dra matically, especially fast -
food restaurants, a large proportion of non - restaurant
outlets such as supermarkets and businesses that previously
did not sell prepared food now do. Food that you
can eat right away ( “ convenience food ” — especially
candy, cookies, chips and sodas) can be purchased in
book stores, car washes, hardware stores and even
building supply warehouses. One survey of multiple
cities estimated that about 40% of non - food outlets in
the United States now sell food (personal communication,
Tom Farley, February 2008). Furthermore, the
availability of vending machines has multiplied several
times over the last couple decades, 19 and these machines
now sell food in office buildings, public buildings,
parks, petrol stations — practically anywhere. And
the types of food items sold are predominantly high -
calorie salty snacks (e.g., chips), cookies, candy and
sugar - sweetened beverages.
Food advertising — cues
Along with increased food availability is the massive
increase in advertising and marketing for food products.
The amount of funds spent on commercial
advertising and marketing research exceeds
funds available for nutrition education more than 10 -
fold.20 – 22 Further, the sophistication of advertising and
the ability to target subgroups has advanced substantially.
Some studies investigating the differential exposure
to age, race and ethnic groups indicate that
children and racial ethnic minorities are differentially
targeted to receive a high proportion of food advertising
not only in television, but in magazines as well. 23
Tirodkar and Jain compared the number of commercials
shown on prime - time shows with African
American characters to prime - time shows with predominantly
white characters. 24 Not only did the shows
targeting African Americans air 66% more commercials
about food (4.8 spots for a 30 - minute show vs
2.9 advertisements for white audiences), but the
advertisements shown to the African - American audiences
were more likely to promote unhealthy items.
For example, 30% of the food commercials for African
American audiences were about candy and chocolate
whereas there were only 14 % for white audiences;
13% advertised soda during Black prime time as
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