While no single study is perfect, all types of studies support a conclusion that a diet that emphasizes fruits, vegetables, whole grains, nuts, fish and unsaturated fats; limits refined starches, sugar-sweetened beverages, and red and processed meat; and excludes industrial trans fat will reduce rates of diabetes, cardiovascular and other diseases, and total mortality.

Confusion is fueled through the extensive coverage of small studies suggesting that being overweight is desirable but not of superior studies including millions of people suggesting the opposite.