Several different theories about food addiction are being considered by the scientific community. Most of us have heard of the “thrifty gene” theory. This theory suggests that people who have this gene will eat more calories today as an instinctive response to the possibility of famine tomorrow.
Another theory suggests that overeating fats and simple sugars is a “rational addiction,” because the cost of withdrawal is higher than the cost of maintaining the habit of overeating. The costs could include the physical symptoms of withdrawal from addictive foods, the costs of weight loss treatment, and the possible higher cost of buying more nutritious meals.
The decisions made by government agencies and individual counselors depend on which of these theories they accept.
If the rational addiction theory is held to be true, laws might be passed to reduce the cost of highly nutritious vegetables and proteins, which are low in calories, and increase the cost of low-quality foods such as sugar and high-fat snacks, perhaps with new taxes. The financial costs of weight loss programs and medications could be lowered with subsidies. Health agencies might create educational and counseling programs to help obese clients make better, less irrational choices when they shop.
On the other hand, if there really is a “thrifty gene” that causes food addiction, scientists would look for ways to “turn off the gene” through new medications or gene therapy. Counseling would consist of helping people recognize their natural tendencies, and help them create an environment in which more rational eating choices would be easier to make. Perhaps governments would regulate the creation and sale of high-fat, sugary foods as if they were an environmental hazard.
To determine which of these theories can be used to explain the very high incidence of obesity and type-2 diabetes among the Pima Indians in the American Southwest, two professors from Arizona State University looked at the shopping activity at several Arizona supermarkets. The study compared the shopping choices at stores near the Pima community, which has an astounding diabetes rate of almost 50%, with those made by the general population at supermarkets in other locations.
The professors determined that the low prices of foods high in simple sugars has led to the over-consumption of these harmful foods in all populations, but that non-native people as a group consume these cheaper foods in lower quantities than do the members of the Pima tribe as a whole. The study did not look at the shopping behavior of individuals.
This may mean that both the “thrifty gene” theory and the economic “rational addiction” theory are correct, and not mutually exclusive. It is true that foods made from white flour and sugar tend to be less expensive (per calorie) than higher quality foods containing protein and whole grains. The easy availability of poor-quality foods, along with high-fat fast food, has had a striking consequence for all Western nations.
Some people do choose to avoid these fattening foods and eat healthy veggies and low-fat meats instead, which lends weight to the thrifty gene theory. However, income does play a part. According to the U.S. Department of Health and Human services, “women of lower socioeconomic status are approximately 50% more likely to be obese than those of higher socioeconomic status.” This statistic includes all racial and ethnic groups.
The incidence of type-2 diabetes, hypertension and heart disease is going up for all Western populations and the long-term effects of this illness are devastating both to the individual and society. In the general population, approximately one-third of American adults are overweight, and a third of these are obese. The occurrence of obesity in the general population has almost doubled since 1960, and is quickly catching up to the high rates of obesity and diabetes among the well-studied Pimas.
Because it is estimated that obesity is related to a 10 to 50% increased risk of death from all causes, and the cost of chronic diseases associated with obesity are creating a drain on the national treasury, it is particularly important to find a workable theory about food addiction. Perhaps if we gain a better understanding of why people overeat, in spite of obvious consequences, scientists will be able to find a cure for the international problem of obesity.