Diet and health: scientific concepts and principles conference commentary

The conference concluded that dietary guidelines are needed, but that they cannot apply to everyone in the population nor to the same extent. Furthermore, a mechanism or structure is needed in which the guidelines can be periodically reviewed and updated. In making dietary recommendations, genetic variability, age, sex and body size need to be considered. Survival, extension of life span, relief of selected symptoms and biochemical improvements of risk factors are some of the criteria to be used in assessing the role of diet in health and disease. The most important questions that remain unresolved in the nutritional sciences concern the relation of diet to the development of chronic disease. The science of nutritional epidemiology needs to be strengthened and etiologic research in epidemiology ought to be performed and evaluated with the same standards used in other branches of science. Therefore, there is a need to establish guidelines for the validity of methods in assessing dietary intake and for a minimum acceptable correlation for the reproducibility and repeatability of dietary intake data. Research on the role of genetic variation and nutrition, the metabolic effects of omega-3 fatty acids and their relationship to omega-6 fatty acids, the energy expenditure after weight reduction and improving the scientific base of nutritional epidemiology will enhance the scientific basis of nutrition and our understanding of the role of diet in health and disease.