We hear a lot of different theories about the current obesity epidemic and why some of us are fatter or thinner. We know that family members tend to resemble one another, but whether this is more of a matter of genes, shared habits, or maybe social pressure, we can’t determine. As a child growing up, I was taught to clean my plate, somehow mysteriously helping children in other parts of the world who didn’t have any broccoli to eat. This habit is very persistent, and I know now to avoid buffets and salad bars.
But the genetic argument is very popular, and recently received a boost from a carefully controlled study. Gregory Livshits and his colleagues at Tel Aviv University and King’s College believe they have found links between genes located on chromosomes 12 and 14 and a woman’s lean body mass by studying more than 3000 middle-aged British women who are either fraternal or identical twins. According to these researchers, differences in the women’s body sizes could be predicted by their genes more than 50 percent of the time, after controlling for age [1].
I’m wondering why these researchers studied only women. I think the guys would appreciate this information, too.
In an interview published on Science Daily, Professor Livshits sounds like a bit of a gloom and doomer: “Women need to know that what they can do about their body weight–especially when they age–is relatively little, and they will do it only with much difficulty.” I get a bit tired of hearing that we all just naturally get fatter as we get older. Just because many of us go that route doesn’t mean it’s “natural.” And yes, dieting is no fun, but if you find the right approach for your way of eating and exercising, I can’t say it is difficult. We found Jenny Craig to be a rather effortless system for weight loss. You eat what they tell you to eat, and you just lose weight and then you maintain the loss. Period.
Livshits et al. are also investigating the possibility of a “skinny gene” test so that women can know ahead of time how easy it will be for them to control their weight. Would you take a test if it were available? I’m not sure I would. I suppose forewarned is forearmed, but the idea of “my genes made me do it” might discourage many women from even trying to control their weight. It could be a handy excuse.
Even if our genes are guilty of making some of us lighter and some heavier, that still doesn’t account for the huge increases in overweight and obesity that have occurred world-wide over the last 30 years or so. I don’t think anyone is arguing that these genes suddenly mutated. True, genes might make some people more or less susceptible to whatever we’re doing to gain all this weight, but that doesn’t tell us why this increase is occurring in the first place.
1. Livshits, G., Kato, B.S., Wilson, S.G., and Spector, T.D. (2007). Linkage of genes to total lean body mass in normal women. Journal of Clinical Endocrinology and Metabolism, 92(8), 3171-3176.
5 Comments
hvitullo · April 6, 2008 at 9:09 pm
I think that there is definitely some truth to the notion that your body shape may be somewhat determined by your genes. Why? Because me and my older sister both have my dad’s legs, awful. However, I don’t think that these genes can be viewed as some kind of scape goat for our society’s obesity problem. I think the biggest problem with obesity is the way our society relates to food. Whether we eat too little or too much, millions of people have a dysfunctional relationship with food. I think we need to focus less on the fact that our body shape and tendency towards obesity may be genetic and more on what we can do to help our bodies now that we are responsible for them. Let’s focus more on eating healthy and getting plenty of exercise!
bwerter · April 7, 2008 at 5:27 pm
I agree with the statement that there is some genetic influence on obesity, however I feel it is something that could be over come if the right amount of effort and probably money were put into it. I also wonder about controlling leptin levels as a way to control weight, like amphetamine’s original use. What would the safety concerns for this be? Would it even work?
Laura Freberg · April 8, 2008 at 10:32 am
It is my understanding that the use of leptin has been disappointing, not because of side effects, but because obese humans already produce high levels of leptin but seem resistant to its normal appetite suppressing functions. So adding more leptin to someone who is resistant isn’t going to do much. Most of the current research is geared towards making existing leptin more effective. For example, see this article:
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=33319
jmgraham · April 8, 2008 at 9:07 pm
I find it interesting that our weight is influenced by our genes. I still think, however, that nurture has the majority pull on what the scale reads. As far as the obesity epidemic, I think it would get even worse if people started taking the test to find out if their genes make them more prone to being heavier. I certainly would not take the test because it would be another discouraging hindrance on getting into shape. People don’t need the excuse that their bodies are destined to be fat because everyone can change their weight with healthy eating and exercise. Also, I disagree with Livshits when in his comment that there is little women can do to change their state. Though it is true that as we age our bodies are not in the same shape and they are more difficult to maintain, I know many many older women who have not only stayed in good shape, but have even lost weight. We can do it!
AprilN · April 22, 2008 at 6:01 pm
I think that genes may play a partial role in determining whether or not someone is going to be obese, but I also think that lifestyle plays a huge role. Someone that has the “potential” to be skinny, can choose to eat poorly and not exercise, and therefore gain weight. But someone who has the potential to be obese, can still make the effort to be active. Althought, it might be easier for some people to lose weight compared to others. I think that regardless if you have the “potential” to being obese, everybody should make a concious effort to try to eat healthier, which means to not only look at the calories, but look at the nutrition components of the food; and exercise.
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