Despite the absence of statistical correlations relating diet and coronary heart disease rates in studies of individuals in natural environments, public and private health organizations and food producers have actively promoted dietary changes for the entire population, not just those at high risk. The result has been a massive risk factor health education campaign that has placed greater emphasis on dietary fats and cholesterol than smoking, physical exercise, and overweight.

The Rise of Public Interest in the Diet-Heart Hypothesis

Throughout the twentieth century, Americans viewed food consumption as closely tied to other aspects of their lives. Early in the century, rising incomes and the greater availability of nutritious foods enabled many persons to reduce their caloric intake without experiencing nutritional deficiencies. Middle-class women, soon joined by men, began to value slenderness in lifestyles and clothing fashions. By 1910 people were speaking of dieting and diets and women's magazines and physicians were providing advice on losing weight. Interest in dieting waned during the depression of the 1930s, the Second World War, and the baby boom of the 1950s but revived thereafter.

Healthy foods were a basic part of health education. In 1917 the U.S. Department of Agriculture began to recommend daily dietary intake levels of foods that supplied essential nutrients. The recommendations were revised periodically and widely promoted in school health curricula and the mass media.