Every five years since 1990, the United States Departments of Agriculture and Health and Human Services collaborate upon and publish a new edition of the Dietary Guidelines for Americans, which are intended to provide everyday citizens with evidence-based recommendations on diet to promote health and reduce the risk of chronic diseases. Through the decades, the advice offered in the manual has steadily changed along with advances in our understanding of modern nutrition.
For instance, take the food pyramid. First introduced within the guidelines in 1992, the original pyramid had a base of whole grain-heavy foods like bread, pasta, cereal and rice — for a recommended six to 11 servings a day — and then ascended level-by-level, from vegetables and fruits to dairy and protein, before peaking with fats, oils and sweets at apex.
