Take a look at the post by Dr. Jay Wortman, a Canadian physician. Dr. Wortman tells the story of the First Nations peoples of Canada who have not responded well to the SAD (Standard American Diet.) Guess what? They DO respond well to the traditional "eskimo" high fat, moderate protein, very low carbohydrate diet.
I've seen native peoples in Mexico and Nicaragua who have gotten very rotund, and on my mission trips see seventeen year olds with type II diabetes. Diabetes is epidemic in south Asia as well. It is becoming a major cause of death, disease, and unhappiness world-wide. The way we're working on diabetes is not working.