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If you have been struggling to fit in your favorite pair of skinny jeans dutifully collecting dust in your closet, you might be fighting more than just diet and exercise. Researchers have identified genetic factors to explain why some people easily put on weight while others with similar lifestyles stay slim.
In industrialized countries, gaining a pound or two a year after age 20 is the norm, which explains why so many of us are overweight by the time we reach 50. There are several factors that help explain this phenomenon, including, but not exclusively, our “super-size-it” habits.
One is the “thrifty genotype.” This hypothesis implies the rapid-rise of obesity is due to multiplication of “energy-thrifty genes” over generations. In other words, when the environment threatened our ancestors with famines, these genes allowed them to store body fat, thus helping them survive lean times. Now that food is plentiful year 'round and our lifestyle more sedentary, these family genes are aiding us in packing on the pounds.
These “fat mass and obesity associated genes” are called FTO. FTO comes in two varieties, and everyone inherits two copies of the gene. People who inherit one version of the fat accumulation gene rather than another are 70 percent more likely to be obese, British scientists discovered.
Researchers at Oxford and the University of Exeter found one in six people has the most vulnerable genetic make-up and weighs on average 7 pounds more than those with the lowest risk. They also have 15 percent more body fat.
In another study, St. Louis School of Public Health looked at 8,000 pairs of twins and found that genes account for more than 50 percent of the change in body mass index as they aged. How we deal with our environment – what we eat, the amount we eat and how much we exercise – accounts for the other 50 percent.
For women, weight gain after menopause can have serious implications for your health. Excess weight increases the risk of high cholesterol, high blood pressure and type 2 diabetes. In turn, these conditions raise the risk of heart disease and stroke.