Philip J. Goscienski, M.D.
February 2009
Some racial groups such as African-Americans, Asians, Polynesians and Native Americans have higher rates of overweight, obesity and type 2 diabetes than others. It might not seem so but this is an exaggerated form of a biological blessing. Humans evolved with the ability to store fat easily during times of abundance, giving them a survival advantage that scientists call the Thrifty Gene phenomenon. In times of plenty an excessive calorie intake leads to fat deposition. It also leads to insulin resistance, which makes glucose, or blood sugar, less available to muscle tissue and diverts it to fat storage. That mechanism served us well until we became smart enough to practically guarantee a steady supply of food. It has turned into a disaster during the past few decades because food has become abundant in every developed country.
A couple of million years ago our ancestors lived from day to day. With no tools and no vessels in which to store food they were at the mercy of nature's whim. In those parts of the world where the food supply was especially variable virtually all the survivors — the entire population — were left with the thrifty gene.
The fat structure of a woman's body is an example of the thrifty gene in action. To every woman's lament, the fat she accumulates on the thighs is remarkably resistant to every attempt to whittle it down through diet and exercise. This is not an accidental quirk of nature. It is assurance that she will have the energy reserves she needs to sustain a pregnancy and the breastfeeding that follows. A woman uses thigh fat very slowly for energy. Her body will break down muscle and other fat stores more readily so that thigh fat will not be used up as rapidly as that which has accumulated elsewhere. Women have also observed, with some seemingly justified resentment, that men respond to stress by losing weight whereas women deal with stress by eating more and maintaining their excess weight.
This is not a perverse act on the part of nature. Moreover, women's fat simply does not respond to the stress hormones in the same way that men's fat does. From a biological point of view, stress represents a threat to the unborn — without which the species could obviously not continue to exist.
There is no single thrifty gene. There are perhaps hundreds of genes that play a role in the complicated chemistry of fat and sugar, the body's primary sources of energy. That makes it unlikely that medical science will ever come up with a single or even a few drugs that will reverse the action of genes that affect fat.
The medical problems that stem from long-term excess fat storage cost the U.S. economy hundreds of billions of dollars a year. This will bankrupt the system within a couple of decades, according to government projections. The solution is to rein in thrifty genes, not to rein in the cost of treating diseases that should never have occurred in the first place.
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.