This study showed what many have advocated. Healthy food with high fat content like meat, nuts, whole milk and cheese were emphasized. Added sugar was eliminated as were grains. The theory explaining the problem with carbs is that they promote insulin release which leads to fat storage. Decades of misinformation, much of it from the government, demonized fat. An excellent book on this topic is The Big Fat Surprise by Nina Teicholz for those who would like to read the whole fascinating story and set the record straight.