January 2010 Newsletter

What to do about the Obesity Gene?

Obesity is said to occur when body fat accumulates over time after calories consumed exceed calories spent. A major health hazard worldwide, it is associated with diabetes, hypertension, heart disease, and some cancers. Recently scientists have begun to question whether genetic differences may leave some predisposed to development of obesity. They are asking, “Is there an obesity Gene?”

In only a generation obesity has literally reached epidemic status in societies throughout the world where there is an abundance of calorie rich foods and little necessity for physical activity. Scientists do not believe genetic code has changed enough in the past few decades to explain the swift increase in obesity. However, there may be a “thrifty” gene that may have helped us survive in prior generations, that is now leading the way for our demise.

The “Thrifty Genotype” Hypothesis might work like this. In prior generations when food was scarce and food sources inconsistent, genetic code may have developed to allow our ancestors to survive hard times and famines by storing fat quickly during years and months when the harvest was plentiful. Unfortunately, those of us with this gene might find shedding pounds more difficult when food sources are abundant such as they are now.

Genes may also regulate our drive to overeat, be active, and even our ability to use dietary fats as fuel, and even our capacity to store body fat.Studies of identical twins, differences among family members, and adoptees lend support to the idea that genetics plays a role in weight gain. For example, research on the FTO gene were first published in Science in 2007, and established a link between Type II Diabetes and elevated BMI in individuals with that code. Indeed, one in two Europeans had some form of the FTO variant, while one in six had two.

Ok, so if we have this gene do we throw in the towel and just play the hand we were dealt? Or, is there anything we can do to overcome our genetics? First, it’s important to understand that even genetics can’t solve the puzzle of the current worldwide obesity epidemic. Only lifestyle changes, increased availability of high density carbohydrates, and the environment can explain the epidemic, since genetics have not changed substantially in the last 50 years since the start of the epidemic. So, for example, changing our present day lifestyles in ways that increase activity levels and reduce food proportions may help reverse the current trends. Eating between meal protein-rich snacks, smaller portions during meals, and finding daily fun ways to stay active are examples of things we can do to combat the obesity gene.

So genetics may help explain our present circumstances, but we can overcome these tendencies in much the same way as did our forefathers, by avoiding a rich diet high in fats and carbohydrates, eating instead a variety of foods, and by staying active.

Sincerely,

Dr. Rob Leach