Since researchers have discovered that there is strong hereditary component in obesity, the search has been on for exactly what genes are responsible, and how much they contribute to our overall weight. Women, more than men, tend to attribute their weight to genetics, and some fitness experts have accused them of making excuses. Are we really victims of our genetic makeup?
Researchers have found a couple of specific mutations – you’ve probably heard about the leptin deficiency gene, which caused a huge surge of interest when it was discovered. Leptin is a hormone that signals our body to stop eating, and children who have this mutation start overeating at around 4 months old, and generally react well to leptin therapy. Despite the interest leptin caused, and the myriad diets published designed to increase your leptin supply or sensitivity, true leptin deficiency is quite rare.
Researchers have decided that genetics probably accounts for about 40-70% of our weight differences. That’s a pretty big range, which indicates, to me at least, that there are many other factors involved in determining our weight. It’s interesting to note, though, that genetics have an effect on adult weight *only* in countries where food is abundant. In other words, if food is scarce, obesity is rare, despite our genetic makeup.
Researchers also suggest that since the “obesity epidemic” (in quotes because there’s a lot of question about whether or not it’s really an epidemic, but that’s another column) began in last half century, we can guess that a lifestyle with more abundant food and less demand for physical activity has a lot more to do with our weight than our genes. There probably isn’t some wacky genetic mutation that just started happening 50 years ago. There is, however, a huge difference in the amount of cheap processed and fast food available. We also, as a whole, have a far more sedentary lifestyle.
Like most things in health and psychology, it’s not all or nothing. Your genetic makeup may have stacked the deck against you, but it can’t determine the end of the game all by itself. Put your focus on eating healthy and exercising your body appropriately, and see what happens. Make sure your goals are appropriate – don’t go for stick-thin if it’s not in your genetic heritage. If your body stabilizes at 15 lbs. above what you wished for, but you feel healthy and energetic, let it be. Jillian Michaels calls these “vanity pounds,” and she may be on to something. Go for health rather than vanity, and you’ll have the control instead of being a victim of your genes.