Monday, September 08, 2008

Exercise cannot control obesity gene associated weight gain

The title on this SciAm summary is silly (emphases mine) ...
Do I look fat in these genes? Exercise can cancel out effects of 'heavy-weight' DNA: Scientific American Blog:

... Physically active people who carry gene mutations linked to obesity are no more likely to be overweight than those without the variants -- as long as they exercise at least three hours a day...
Exercising 3+ hours a day is not compatible with life in a post-industrial world. If these results turned out be generalizable to a reasonable portion of the obese population (big if), then we'd know that exercise won't control our expanding (sorry) obesity problem. We already know diet doesn't work, so here's hoping for great drugs ...

Either that, or we get rid of our cars ...

Update: see a good comment critiquing this post

3 comments:

GZ said...

First, the number of folks who carry gene mutations that are linked to obesity, as I understand it, is very small. I can't point to an article (nor have I read this one) but I understand it to be less than .1% of of the population.

That said, we tend to drive obesity in our culture based on the choices we make - namely the food choices we make.

Second the the standard for exercising in these studies is ridiculously low. We are not talking about running a marathon. We are talking about basic movement ... like walking, washing dishes, taking the stairs, etc. If we excuse ourselves from this standard, we are choosing to not be good animals and are killing ourselves. We'd be better to get up from our desks and walk around during those conference calls.

My concern is this study could further perpetuate the idea that obesity is a fate folks need to live with and something they cannot overcome. There is some truth to that of course, but not for the huge majority of us.

John Gordon said...

Great comment. I did use 'big if' as my way of sneaking buy the limited explanatory power of known gene mutations.

The history of the past 2-3 years is that a large number of varying collections of a large number of possible gene variations contribute to most phenotypes. Obesity is probably no different, so each obese person is more or less obese in their own way.

That said, this is not the only study that has cast doubt on how well exercise will control weight in all but the most diligent and disciplined individuals.

On the other hand, people who exercise can be technically obese (but the rather strict federal guidelines) and still be very healthy and even athletic.

GZ said...

It is worth noting that it has been found genetic expression can actually be changed by choices in our life style. The so called "Med Diet," exercise, not smoking, limiting alcohol intake, etc ... you can change you genetic expression.

Certainly genetics has HUGE amount to do with who we are. Rather than have that dictate what we are, it is much more empowering to choose WHO we are physically.