Guests:

• Dr. Katherine Flegal: senior scientist at the Centers for Disease Control and Prevention.
• Dr. David Katz: director of Yale’s Prevention Research Center and editor-in-chief of Childhood Obesity.

We’re all aware of the cons of carrying around extra weight. Those who are overweight are more susceptible to heart disease, diabetes, and other health problems. But recently Dr. Katherine Flegal of the Centers for Disease Control and Prevention discovered a possible pro — many people who are overweight outlive their skinny peers.

Bigger is Better?

“For the overweight category, technically we use a Body Mass Index of 25 up to 30,” Flegal explains. “What we found was that in about 80 percent of the studies, or 70 to 80 percent, the results actually showed a slight reduction in mortality, relative to the normal weight category.”

Flegal is quick to point out that the decreased risk of death was slight — under one percent. But to a medical community that had long asked the overweight to slim down, the results were surprising. For Dr. David Katz, the director of Yale’s Prevention Research Center, Flegal’s findings are a healthy reminder that medical professionals should be willing to rethink the wheel.

“We can’t fall in love with a particular view of the world,” he says. “If we were to find that, when we really look carefully, people with a Body Mass Index of 25 are healthier — not just more years in life, but more life in years — if that were true, we would need to pay attention, and we would need to expand the range that we define as normal or optimal.”

Deceptive Data

But while he’s willing to keep an open mind, Katz doesn’t think that you should reach for another cookie. Studying only Body Mass can be deceptive, he argues. The measure, which is a ratio of weight and height, would define a body builder as morbidly obese. Looking at merely whether or not an overweight person lives longer than a skinny person isn’t a good way to measure health, he argues.

“We have epidemic diabetes in adults and children alike, and we know that’s because of excess body fat,” he says. “As a doctor, I can tell you we’re pretty good at using the cutting edge of biomedical technology to prevent death. But we’re not nearly as good at cultivating health.”

Health, Not Weight

But Flegal is disappointed that the medical community has been dismissive of her findings, which she thinks are a continuation of prior research rather than a radical departure.

“They kind of ignore this finding that being overweight might be slightly protective because they are uncomfortable with it, or they might get criticized for it, as has been my experience,” she says. “But we’re not reporting anything that’s really new, and our studies that we use cover wide ranges of types of populations … and almost 80 percent of them show that overweight is slightly reduced mortality. So I don’t think this should be treated as a chance finding.”

But there’s one thing that Flegal and Katz can agree on — analysis of obesity should be based on measures of health, and not on what any individual looks like.

“The reason to care about weight, as health care professionals, as a society, is not because of what we see in the mirror,” Katz says. “We can all decide if we’re happy with that, or we’re not happy with that. But this really is about health — important health outcomes and mortality.”

So no matter what your weight, Flegal and Katz say, talk to your doctor about your health.