Maybe you don’t like to exercise because of a gene passed down from your ancestors rather than any feeling of laziness. If you would rather sit on the couch and watch football games or a movie instead of going to a gym the inertia may due to the same type of gene that determines how tall you will be or how much you will weigh rather then some will power defect. There are simply too many very smart, successful people who have energy to accomplish every task they face in their lives except one-the task of exercising– to write it all off to simple laziness. Sometimes, simply understanding some of the factors making it difficult for some people to lose weight and to exercise can alleviate frustration for people by helping them to set more reasonable goals.
Genetic predisposition can trump environment and will power and render some people thin while others fat. Several past studies have linked genetic variants to obesity, but none have been found to be the sole cause for the disease. Searching for a gene to explain diabetes, researchers in England discovered the gene known as the FTO gene. (Fat Mass Obesity Associated Gene). This genetic variant occurs in over half of people of European descent and is involved with the regulation of body fat.
The strength of the genetic influence depends on whether an individual has inherited one or two copies of the FTO gene variant. A person with two copies of the FTO variant is likely on average to weigh 6.6 pounds more than a person who does not have the FTO variant at all, and if they have only one copy they are likely on average to weigh 2.6 pounds more. People with FTO eat roughly 100 more calories per meal. In addition, they chose foods containing high levels of sugar and fat, suggesting that they were instinctively drawn to those types of food.
In the US, the FTO gene was found to be especially prevalent in the Amish people in eastern Pennsylvania. A subgroup of Amish farmers with two copies of the FT0 gene were only able to maintain their weight by exercising 3-4 hours a day and burning 900 calories. “This is the first time that we can show the direct gene-environment interaction for a gene related to obesity,” researchers reported. “We can compensate for our genetic makeup by our lifestyle choices – by watching what we eat and how much we exercise.” genee
J. Timothy Lightfoot at the University of North Carolina, Charlotte, reports that genetics may indeed predispose some of us to be couch potatoes. Using mice specially bred and selected according to their activity levels, Lightfoot identified 20 different genes that influenced activity levels – specifically, how far the animals will run. Exercise-prone animals ran 5 to 8 miles per day and night on an exercise wheel while inactive mice ran only 0.3 miles per day. Some of the sedentary mice found ingenious ways to avoid activity. One stuffed wood shavings around the wheel and turned it into a bed; another used it for a toilet and another climbed on top and used it for a look out tower. It sounds kind of familiar, like using treadmill or elliptical handles to hang clothes in a home gym.
There are two theories to explain the differences in activity levels: genes may affect either the way muscles work – by making them more efficient and preventing fatigue or effect some higher-order biochemical circuit in the brain, such as levels of the neurotransmitters dopamine or serotonin. Either way, the result is to encourage exercise.
Other clues to the role of genes in the desire to exercise are found in the intensive study of identical twins in some of the Scandinavian countries. A Swedish twin study found that among identical twins 57% exercised, while non identical twins only 25% exercised, despite varying environments. In a Quebec family and twin study, physical inactivity was found to be more genetically related than time spent in moderate to strenuous exercise which was less related to hereditary. stylowakobieta
Once again- the familiar formula of “calories in and calories out” may be too simplistic to explain all the variables that regulate our desire to exercise and thus lose weight. Simple models of self restraint and will power do not explain what we see. That does not mean that the individual with genes predisposing to gain weight or inactivity should give up, he just needs to work a little bit harder, learn new behaviors and adapt to new situations.
