So the researchers looked to the genetic data, and indeed, there were two specific genes that stood out related to patterns of fat loss and exercise. Participants with certain combinations of those genes and their variants had significantly different fat loss outcomes.
The complex science at this level can be pretty confusing. Genes are named with different alpha-numeric characters, and so are their variant alleles. If you're not careful, you can end up in some real alphabet soup just trying to talk about it, but basically two genes are involved here: the CYP19 and the COMT.
Researchers found that having one CYP19 gene and its variants was not consistently associated with percentage fat, total fat, subcutaneous fat or intra-abdominal fat, the dangerous excess that gathers around our vital organs.
But having two such genes correlated to a slightly larger decrease in body mass index and a significantly larger decrease in total fat and percentage of body fat.
And having a particular genotype of the COMT gene, together with at least one copy of the CYP19 gene, also related to a significantly larger decrease in BMI, total fat, and percentage of body fat. There were corresponding intermediate combinations and results that bore out the relationships.
Interestingly, in the exercising group, those with a specific variant of the CYP19 gene lost more fat over the year, but in the nonworkout group, those with that same variant gained more fat.
Why and how these genes affect the fat/exercise relationship isn't yet understood, but now that these have been identified as significant, they are the subject of much new, focused study. Other research has since showed that women with that specific CYP19 variant have higher concentrations of the hormones estrone and estradiol, which may make them more resistant to fat loss through exercise.
Obviously, everyone can't go for genetic testing before embarking on a weight loss effort. And where the rubber meets the road, it may not even matter what specific genetic makeup you have that could be adding to your difficulty.
The important thing is that this research shows once again that the calories-in, calories-out explanations about body weight are just too simplistic and don't account for many very real variables that have nothing to do with will or self-restraint. Many people have always known this at gut level, but it's good to see the science bear that out.
That said, people shouldn't assume that they're genetically precluded from ever being thin and healthy. Remember that natural love of athletic activity we mentioned? You might not be born with it, but you can learn new behaviors and adapt.
Nowadays, we have all sorts of ways to overcome our genetics. We take medications, we dye our hair, we even wear colored contact lenses! The exercise plan that got your sister so svelte may not work for you, but something will.
So if you're one of those with the bad hand, don't give up! A dietary and weight management program could be tailored to address your very specific needs in order to get and keep your weight in check. Because getting dealt a bad hand doesn't doom you to losing the game -- it just means you need a different strategy for winning it.
Thick and Thin
If you've earnestly tried to drop weight, and your results just don't ever seem to stack up very well next to your pals', that can be very demoralizing. But it may be that you're subject to certain resistant genetic factors. Sometimes, simply understanding the cards they're holding can alleviate a lot of the frustration for people by enabling them to set more reasonable expectations, and helping them take a fresh start at getting healthy.
Caroline J. Cederquist, M.D., is a board-certified family physician and a board-certified bariatric physician (the medical specialty of weight management). She specializes in lifetime weight management at the Cederquist Medical Wellness Center, her Naples, Fla., private practice. You can also get more information about Dr. Cederquist and her weight-management plan by visiting www.DietToYourDoor.com. She is the author of Helping Your Overweight Child: A Family Guide, which is available at DrCederquist.com or by calling toll-free 1-800-431-1579.
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