Both the quality and the quantity of food ingested are relevant to the genesis of risk factors for coronary heart disease and the two are inseparable. Nevertheless they have a major common pathway through hypertension, which may well be the most important consequence of a high-protein, high-carbohydrate, high-fat, high-energy and high-sodium diet. Because body fatness is a strongly genetically determined characteristic and because it evolves over the whole period of childhood a vigorous and sustained programme of health education is required at all levels. The aim of such a programme is to effect a small shift in the fatness of the whole population; such a shift would dramatically and disproportionately reduce the incidence of obesity. Since the morbidity and mortality which is found in obese subjects arises primarily from cardiovascular disease in general, and coronary heart disease in particular, nutritional influences have obvious relevance to the prevention of coronary heart disease.