Dietary fats, eating guides, and public policy: history, critique, and recommendations.

Controversies over the nutrition science of dietary fat, and equally over the advice furnished to consumers about dietary fat, have confounded US nutrition policies and eating guidance for the last 90 years. This is so despite the remarkable congruence between the first US food guides (1916) and the most recent (2000 Dietary Guidelines for Americans), both of which state that dietary fats should be consumed "moderately." The 2002 Report of the US Food and Nutrition Board (issued jointly by the United States and Canada) quantifies this by stating that healthy dietary fat should constitute "25-35 percent of calories." However, the US consumer guide, the Food Guide Pyramid (released in 1992 but based on data from the early 1980s) states that dietary fats should be consumed "sparingly," which is explained to be "a diet low in fat." This direct conflict in official dietary policies causes consumer confusion and erodes efforts of public and private health promotion efforts to stem the increasing incidence of overweight and obesity in Americans. The most successful population-wide dietary behavior modification program in US history was the food rationing program in World War II. Its successes were based equally on consensus nutrition profiles for good health and messages that communicated the rationing program effectively. The current US incidence of overweight and obesity, and the chronic diseases to which they are precursors, will be mitigated and prevented only with major changes in national dietary policies and programs based on successful experiences and models. The first step in this much-needed process is acknowledgment that current dietary guidance and education policies have been and are unsatisfactory.