Food Politics: How the Food Industry Infl uences Nutrition and Health 319Does Diet Matter?
In addition to consuming largely plant-based diets, people in long-lived popula-
tions are physically active and burn up any excess calories they obtain from food.
An active life-style helps mitigate the harmful effects of overeating, but the evi-
dence for the importance of diet in health also is overwhelming. Disease by chronic
disease, scientists consistently have demonstrated the health benefits of diets rich
in fruit and vegetables, limited in foods and fats of animal origin and balanced in
calories. Comprehensive reports in the late 1980s from the US and Europe docu-
mented the evidence available at that time and subsequent research has only
strengthened those conclusions.^4
Health experts suggest conservatively that the combination of poor diet, sed-
entary life-style and excessive alcohol consumption contributes to about 400,000
of the 2,000,000 or so annual deaths in the US – about the same number and
proportion affected by cigarette smoking. Women who follow dietary recommen-
dations display half the rates of coronary heart disease observed among women
who eat poor diets, and those who also are active and do not smoke cigarettes have
less than one-fifth the risk. The diet-related medical costs for just six health condi-
tions – coronary heart disease, cancer, stroke, diabetes, hypertension and obesity –
exceeded $70 billion in 1995. Some authorities believe that just a 1 per cent reduction
in intake of saturated fat across the population would prevent more than 30,000
cases of coronary heart disease annually and save more than a billion dollars in health
care costs. Such estimates indicate that even small dietary changes can produce large
benefits when their effects are multiplied over an entire population.^5
Conditions that can be prevented by eating better diets have roots in child-
hood. Rates of obesity are now so high among American children that many exhibit
metabolic abnormalities formerly seen only in adults. The high blood sugar due to
‘adult-onset’ (insulin-resistant type II) diabetes, the high blood cholesterol and the
high blood pressure now observed in younger and younger children constitute a
national scandal. Such conditions increase the risk of coronary heart disease, can-
cer, stroke and diabetes later in life. From the late 1970s to the early 1990s, the
prevalence of overweight nearly doubled – from 8 per cent to 14 per cent among
children aged 6–11 and from 6 per cent to 12 per cent among adolescents. The
proportion of overweight adults rose from 25 per cent to 35 per cent in those
years. Just between 1991 and 1998, the rate of adult obesity increased from 12 per
cent to nearly 18 per cent. Obesity contributes to increased health care costs,
thereby becoming an issue for everyone, overweight or not.^6
The cause of overweight is an excess of calories consumed over calories burned
off in activity. People gain weight because they eat too many calories or are too
inactive for the calories they eat. Genetics affects this balance, of course, because
heredity predisposes some people to gain weight more easily than others, but
genetic changes in a population occur too slowly to account for the sharp increase
in weight gain over such a short time period. The precise relationship between the
diet side and the activity side of the weight ‘equation’ is uncertain and still under