Background: A science-based diet approach to achieving a healthy diet began in the early 1900s, and this led to the development of the United States Department of Agriculture's (USDA's) Food Guide Pyramid. Since its adoption, the prevalence of overweight and type 2 diabetes has risen substantially. Whether the two are related is unknown, but a change may be needed in the way the government recommends that Americans eat.
Methods: The purpose of this review is to propose a new diet that is based on two novel strategies: a low-glycemic load (GL) diet and a unique macronutrient composition. Most of the carbohydrates in the proposed diet have low-glycemic indexes (GIs), which creates a diet that has a low-GL. In contrast, the USDA's Food Guide Pyramid diet recommends consuming a high carbohydrate diet (i.e., >55% of the energy), which is rich in grains and other complex carbohydrates that have high-GIs. In clinical studies, low-GL diets produced less hunger, promoted more weight loss, and improved markers of glycemic control and cardiovascular disease risk compared to the usual, high-GL diet under eucaloric conditions. The other feature of the proposed diet is its unique macronutrient composition of 40% of the energy from carbohydrate, and 30% of the energy each from protein and fat.
Results: The diet recommended now has a macronutrient percentage of >55% of the energy coming from carbohydrate, 15% of the energy from protein, and <30% of the energy from fat. Compared to the USDA's Food Guide Pyramid diet, clinical studies using the proposed unique macronutrient percentages have shown increases in metabolic rate, dietary theromogenesis, and nitrogen balance.
Conclusions: The advantages of the proposed diet should benefit all Americans, but more long-term studies are needed before it can be adopted as the national diet.