THE BLOG
06/16/2010 09:14 am ET | Updated Nov 17, 2011

The Obesity "Paradox"

By now, most people have heard about the so-called obesity paradox, the notion that mortality rates go down for people who are overweight or obese (and are highest at either end of the spectrum, where people are underweight or very obese). This finding has confounded obesity researchers so much that they named it the obesity paradox. Because obviously being fat is bad for you, and if the research doesn't back up this idea, there must be something wrong with the research.

We're so conditioned to believe that losing weight is good for you--especially if you're obese--that most of us don't question this idea. But a new study from NHANES (the National Health and Nutrition Examination Survey) shows that when people over 50 years old of varying ethnicities lose weight, their mortality levels go up. In this study, overweight/obese men and women who lost between 5 and 15 percent of their body weight were at an increased risk of death than those who lost less than 5 percent or didn't lose weight at all. Oh, and this was after correcting for factors like smoking and illness, which is important because some researchers try to "explain" the obesity paradox by saying that thinner people in the studies were already sick, or their health was already compromised because they were smokers. Not so.

Interestingly, researchers concluded that this increased mortality held true no matter how high a person's BMI was in the first place. In other words, even if your BMI was, say, 40--a number that would cause most obesity researchers and many primary care docs to froth at the mouth--losing weight made you more likely to drop dead.

It seems clear that we don't really understand weight and metabolism yet. That we don't know why these findings are true. One factor that seems to be emerging is that one of the riskiest behaviors, weight-wise, is weight cycling--gaining and losing weight, often the same amount of weight, over a period of time. This study seems to confirm this correlation, at least when it comes to weight loss. We have a lot to learn about why this is so, and I look forward to following the research on this.

What we do already know, though, is that there's a profound disconnect between our cultural attitudes around weight and weight loss and the reality. I'm thinking of one of the most egregious shows ever aired, The Biggest Loser. Even before reports leaked of the dangerous practices that are standard fare for contestants on the show--fasting, dehydration, severe caloric restriction--the show made many people cringe for its dim-witted insistence that fat is always bad and thin is always good, end of story. Oh, and for its willingness to exploit people's deepest vulnerabilities to make money. But if we look at the tactics of this and other weight-based reality shows now, they begin to look not just tacky and offensive but dangerous.

And that's the real paradox: that we're so willfully blind to the way we conflate weight and health that we can't see the difference even in the context of a demeaning show like this one. We persist in thinking that fat = death even when the scientific evidence clearly demonstrates otherwise.

I guess for some people, the world will always be flat, no matter how many times they sail around it.