Nutrition: the need to define "optimal" intake as a basis for public policy decisions.

Much of the current chronic disease incidence, notably coronary artery disease and certain types of cancer, relates to nutritionally induced metabolic overload. The evidence for this conclusion is based on extensive analytical, descriptive, and metabolic epidemiological investigations as well as critical experimental studies in animals. Dietary assessments within homogenous populations, because of inherent measurement errors and similarities in eating habits, make only limited contributions to this issue. This communication makes recommendations as to an "optimal" diet, especially for fats and fibers, as a goal for effective disease prevention that is within our reach with the appropriate support of an informed public and a cooperative food industry. To facilitate effective public health action, the "optimal" diet is called the 25/25 diet, that is, 25% of calories as fat and 25 g per day of fiber.