Philip J. Goscienski, M.D.
March 2009
Do you feel that you have a genetic tendency to be overweight because most of the people in your family are? It's hard to deny that there is a fat gene when even identical twins often share the same affliction.
Native Americans of the Pima tribe have a genetic tendency to accumulate body fat but that doesn't condemn them to becoming obese. Several centuries ago the Pimas separated into two groups, the one settling in Arizona and New Mexico and the other in central Mexico. They haven't intermarried with other tribes very much so that their genetic pattern is virtually identical in both groups and to that of their ancestors. But how they differ from each other!
Mexican Pimas weigh, on average, about 57 pounds less than their American cousins. They also suffer much less from obesity-related diseases such as coronary artery disease and type 2 diabetes. If they all have the same fat genes, how do we explain the huge differences?
Mexican Pimas work hard at providing food for their families, spending about 27 hours a week in moderately intense physical activity. With no supermarkets or fast-food outlets they eat as their ancestors did, mostly vegetables, whole grains and lean meat. In contrast, their northern relatives spend fewer than 5 hours a week in moderate physical activity and they live mostly on refined carbohydrates.
Nature has programmed us to overeat during times of abundance. Humans who were lucky enough to have fat genes and acquired some fat stores could make it through periods of food scarcity and used up that fat. That was especially true in places like Polynesia, Micronesia and the Americas. Modern survivors in those parts of the world now have stunning rates of obesity, as high as 80 percent, and type 2 diabetes, nearly as high.
It's hard to put on excess fat if your diet consists of wild plants and wild game. The former have stomach-filling fiber and the latter has little high-calorie fat. Analysis of Stone Age human remains and studies of present-day hunter-gatherers show that they ate 3 to 5 pounds of plant foods every day to satisfy the needs of their hard-working lifestyle.
Nature didn't make a mistake. You can foil your fat genes with a diet that is high in calorie-sparse vegetables and lean meat and low in refined flour and sugar. That's simple. Too bad it's not easy!
Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at drphil@stoneagedoc.com.