The latest battle in the fat wars: obese triathletes. A burgeoning movement these days, casually known as “fat but fit”, promotes the acceptance of obesity in sport. Just as we’ve known for years that overweight individuals can have low LDL cholesterol and blood pressure, the thinking goes that obese folks can be fit and healthy despite being, well, enormous. I’m going to restrain myself on the triathlon commentary (for now) but I do want to discuss the general issue here.
The movement lends itself to a larger debate over the alleged risks of obesity. For decades it was simply accepted wisdom that obesity meant increased risk for illness and disease across the board. CHD (coronary heart disease), type 2 diabetes, arthritis, depression, cancer, you name it, and obesity was likely to increase the chance you’d get it. And the wisdom was well vetted by literally thousands of peer-reviewed studies . The only thing obesity didn’t do was raise a person’s osteoporosis risk (carry around a lot of weight, and your bones are going to respond out of necessity).
Enter the counter arguments and the acceptance police. No one ever questioned the fact that obesity – even being slightly overweight – is flat-out bad for your health. Until Katherine Flegal, that is. Flegal is a CDC researcher who found that the statistics were actually bearing out an unlikely conclusion: being a little bit fat is better than being lean. Journalists and authors quickly published a slew of writing questioning the reigning fat hypothesis . Conspiracy theories followed in short order (of course doctors and drug makers would fuel the obesity-is-risky hype: there’s money to be made). Americans alone spend $33 billion a year on weight loss , and the number continues to increase (one reliable estimate  that includes healthcare-related costs is triple that number). Obesity, so the debunkers claim, is pure myth manufacturing . Two-thirds of Americans aren’t obese; it doesn’t kill 400,000+ people a year; it doesn’t shorten your lifespan. And on and on.
There’s a great deal of romance here: just enjoy life and savor food, and the problem will take care of itself. We worry too much about calories. Americans are extremists – we hate carbs, then we hate fat, then we hate carbs again. Look at those French, enjoying their cheese and wine and croissants and managing to be trim – we could learn a thing or two. You could even make a rather persuasive “primal health” argument that obesity would be smarter in an evolutionary sense, since your body would have readily available fat stores with which to survive shortages or famine. Romantic and catching ideas, to be sure, but that’s the problem: no scientific studies bear any of this stuff out. Beyond that, the counter-evidence is lousy. For example, some of the lean folks in Flegal’s study were smokers and/or chronically ill. And in fact, a leading researcher  points out that the “overweight people are healthier” case has been recycled several times in recent decades.
Good headlines, wobbly science (and the French are dealing with an obesity problem, too). The facts remain: both obesity and being moderately overweight are unhealthy.
That said, how do we define obesity? I think that’s a major issue we’ve got to address. Admittedly, the BMI is a near-useless metric. It can’t account for bone density, lean muscle mass, individual physique, or adiposity (fat). You can be rail-thin but in terrible shape, and get a clean bill of health if you go by the BMI. Likewise, you can have a bigger build, but be maintaining a very low body fat percentage, and you’re gonna get classified as obese.
Obesity is a problem, but so is the way we define it.