I went back to Dr. David Katz's classic article published in the Harvard  Health Policy Review in 2006. His example of the Pima Indian tribe had caught my eye the first time through the piece and serves as a cautionary note for the rest of us. I decided to explore the subject further.

mesquite tree

The Pimas, who live not far from us, in the four corners region where Arizona, Colorado, New Mexico and Utah meet, used to be outdoors men and women, taking long-distance walks on a regular basis and eating a diet that fits all the modern parameters for healthy eating. it included two unusual items one of which was mesquite,  which I think of as a tree. I've now found that mesquite has bean pods that can be dried and ground into a sweet,nutty flour high in calcium, magnesium, potassium, iron and zinc, and rich in the amino acid lysine.

The other native foodstuff was a drought-resistant bean, tepary, which has recently been introduced into African agriculture . All in all they exercised much more than many of us and ate a high-fiber, low-fat low-sugar diet without an abundance of calories.

Then civilization happened to the Pimas. Now they own casinos and don't walk anywhere as far as their forebears (their per capita income is still on the low side). They also eat a less healthy "American diet" similar to the rest of us.

The consequences were those you'd expect. obesity and diabetes. Fifty percent of the adult Pimas are obese and of those 95% have diabetes. The tribe is now part of a major NIH research project (the website is at http://diabetes.niddk.nih.gov/dm/pubs/pima and then add /pathfind/pthfind.htm or /obesity/obesity.htm), which over the past 30 years has shown that before gaining weight, overweight people have a slower metabolic rate.

This so-called "thrifty gene" theory originally suggested in 1962, looked at populations, like the Pimas, who over thousands of years would have alternating period of famine and feast. When there was little to eat, they stored fat. Now that they don't need to do this in the same fashion, the gene has led them toward the diseases associated with obesity, especially diabetes.

less healthy than mesquite flour

An update from the Harvard School of Public Health mentioned the mayor of Boston having banned sale and advertising of "sugar-loaded drinks" from city-owned buildings and city-sponsored events. The chair of HSPH's Department of Nutrition was quoted as saying, "There is abundant evidence that the huge increase in soda consumption in the past 40 years is the most important single factor behind America's obesity epidemic."

So not all of us have thrifty genes to blame for weight gain. But we can start by abandoning those sodas and other sugar-laden drinks.  And perhaps, to whatever extent we can, returning to a diet similar to our own ancestors, with more locally grown fruits and veggies leading the way to better health.