My research has shown me that people who have lived in the same ecological niche for 500-1000 years "adapt" physically and culturally to a diet and exercise regime that supports good health for that niche. Relatively rapid change in diet and exercise, unbalances their system and produces ill effects. They are right on the diet part but they also need to look at how much daily exercise a typical child and adult got 100 or more years ago and figure out how to get - grin - people moving again and not doing as so many of us do - watch tv and sit behind a computer instead of taking a walk or a run.
Tohono O'odham turns to traditional foods
"The second largest Native American tribe, Tohono O'odham, has the highest rate of adult onset diabetes in the world. Many of the tribe's 28,000 members live on a reservation in the desert in the U.S. southwest state of Arizona. Until 1960, no one had diabetes because people ate traditional foods that helped prevent the disease. But with the introduction of foods high in fat and calories, diabetes became widespread, including in children. Now the O'odham people are being encouraged to go back to eating the traditional foods and a cafe on the reservation is making those foods appealing.