Travis

Just so we’re all clear on this, my problem was with the New York Times using the word “protective,” not the science itself. Thanks for the clarification.

Thanks for bringing up this article, it’s an interesting one and I’ve been waiting for it to make a splash in the blogosphere! As usual you make some good points, and I would like to point out a couple things to help put this research in context. I apologize for the length, but it’s a topic near to my heart

The main issue, which was alluded to by Hanlie, is that BMI is a crude measure of body fat. More and more research, including most of the work that I have been involved with, has shown that it’s not how much body fat you have, but where you store it. For example, body fat stored in the legs has consistently been shown to protect against metabolic risk in longitudinal studies (I just published a study showing that lower body fat is associated with improved health in elderly men and women, which is available here). In contrast, abdominal fat, and in particular visceral fat, is independently associated with increased risk of morbidity and mortality. People who have high BMI’s tend to have high amounts of visceral fat, which is probably what drives the relationship between BMI and health risk. However, some people with high BMI’s store body fat mainly in their lower body (the “pear” body shape), and these individuals often have very little metabolic risk at all. Similarly, although less common, some individuals with a high BMI are merely very muscular (these people also have low health risk).

On that note, I respectfully take issue with your title, because this study does NOT suggest that body fat is healthy (even though research suggests that it’s not always unhealthy either, even in very large amounts). The current study suggests that high BMIs were associated with health, and that is very different from saying that body fat is healthy. It gets confusing because obesity is currently defined using BMI, but many people (myself included) are trying to get the focus off of BMI, because as you’re probably noticing, there are a lot of reasons why it is not an ideal way to define obesity.

I’d also like to point out that obesity is not always a death sentence, in fact the work of Steve Blair and others has shown consistently that obese and active individuals are healthier than those who are lean and inactive. This is probably partly because physical activity preferentially reduces visceral fat, leading to dramatic health improvements with little or no weight loss. In a similar vein, a paper just came out showing that even in individuals who are classified as “lean” according to their BMI, those with greater amounts of abdominal fat are at increased health risk than those who have lower amounts of abdominal fat.

And lastly, I’d just like to mention that just because a study causes some confusion, it does not mean that the study was poorly done, or that it is irresponsible. I know that it is strange and somewhat counter-intuitive that being obese can protect against metabolic risk if the fat is stored in certain locations, but it’s a consistent and accepted finding. Unfortunately there is a tremendous amount of nuance in body composition research, and that is hard for the mainstream press to properly articulate. People also have a lot of emotional investment in the “fat=bad” line of reasoning, but it’s just not that simple (which makes my life much more difficult).

So while the mainstream press coverage might fail to properly explain the research in context (as it usually does), I get worried when I see people attack the research itself, which as far as I can tell was well done, and delivered a finding that is not very controversial at all when viewed in context of other research.

I will now climb down from my soap box…

Travis

I think the real problem is the reporters who base their analysis on a press release and a few interviews rather than true critical expertise. It is tough to demand post-graduate science degrees from our journalists, however.

In the past these studies remained inside the scientific community which allowed quality critique. With the internet and 500 TV channels along gobs of talk radio, mass media is on the constant lookout for a headline. It would be nice to allow a time for critique and analysis prior to the consumption by mass media, but I think the cat is out of the bag. All we can do as consumers is do as you said and “be skeptical of what you read”