Potential responses to and impacts of epidemiological and experimental data on dietary fat and cancer. Dietary...

The majority of dietary guidelines discussed above suggest a reduction in the % of dietary calories derived from fat. Currently, approximately 40% of calories in Western countries come from fat. Some of the more recent guidelines call for a reduction in fat intake to 30% of calories. Indeed, the Committee on Diet, Nutrition and Cancer (National Academy of Sciences 1982) and the World Health Organization Report on Prevention of Coronary Heart Disease (WHO 1982) suggested that the evidence warranted an even lower fat intake, but 30% of calories is a moderate and practical target. Diets containing 30% of calories as fat are undoubtedly safe for the general population. During and immediately after the Second World War in Britain, dietary fat intake was at or about this level and no deleterious effects in the population were noted. (Greaves and Hollingsworth 1966). Indeed, the overall state of health of the population seemed improved. Furthermore, most of the world population exists and has existed on a primarily plant based diet, low in fat content, with no apparent ill effects and lower rates of chronic disease. (Mintz 1985). Most dietary guidelines recommend a reduction in saturated fat intake. The more recent guidelines suggest saturated fat should be restricted to less than 10% of total calories. While some of the earlier guidelines suggested an increase in polyunsaturated fat intake, more recent guidelines stress that polyunsaturated fat intake should not exceed 10% of calories. Thus, the focus of more recent guidelines appears to be to decrease total fat intake. Essentially all guidelines stress avoidance of obesity by avoiding excess caloric intake and increasing caloric expenditure. Diets low in total fat content are beneficial in this regard, a fact acknowledged in the Food and Nutrition Board's report "Towards Healthful Diets." (Food and Nutrition Board 1980 b) Most guidelines advise a decrease in calories derived from processed sugars and a concomitant increase in complex carbohydrate intake. This is best achieved by stressing whole grain cereals, fruits and vegetables in the diet. More recent recommendations advise moderation in the use of alcohol. Moderation in salt use is also a common theme. It is our belief that guidelines should be general in nature and not identify specific nutrients, e.g. vitamin A and C in foods, or specific foods themselves, e.g. cabbage, as conferring special benefits. The available data base does not support such specific claims.(ABSTRACT TRUNCATED AT 400 WORDS)