Study: Big Behinds May Benefit Health

Being bootylicious has helped many a hip-hop career, but now Harvard Medical School research has found that it can also help your health.

A study led by HMS professor C. Ronald Kahn found that the kind of fat that has made Jennifer Lopez famous—fat found in the buttocks and thighs—may actually help prevent diabetes.

Those with generous derrieres, or “pear-shaped” bodies, store subcutaneous fat in their hips and buttocks. Those with “apple-shaped” bodies tend to store weight around their abdomens.

Researchers already knew abdominal obesity came with a higher risk of diabetes and cardiovascular disease.

What Kahn wanted to know was what would happen if the fat from the two areas was switched. So he injected lower-body fat from mice into their abdomens.

“What we found was that moving the fat under the skin and hips...actually improved metabolism,” Kahn said in an interview.

Mice with the transplanted fat lost weight, had lower insulin levels, and had better insulin sensitivity.

Kahn had found that not all fat is created equal: subcutaneous fat from the lower body, it turns out, is very different from abdominal fat.

What the difference is, exactly, has yet to be discovered. That kind of finding would have “enormous implications” for the understanding of obesity and diabetes and for the pharmaceutical industry, said Philip Gorden, the former director of the National Institute of Diabetes and Digestive and Kidney Diseases.

Those who aren’t fortunate enough to be callipygian, however, can’t do much.

“It’s very hard for people to control their fat distribution,” Gorden said. “What they can control is the quantity of fat.”

Procedures like liposuction have been shown to have no effect on diabetes, Kahn said, but fortunately, when people lose weight, they tend to lose abdominal fat first.

Kahn’s work, said Gorden, is more about understanding the fundamental “why” of risk. “We need to keep searching for central mechanisms that control why abdominal obesity confers so much risk,” he said.

Kahn is now exploring the questions that his findings have raised.

“What we are trying to do now is to show if transplanting fat would actually protect you against diabetes or bad effects of obesity even if you’re on a high-fat diet,” he said.

“Secondly, we’re trying to...isolate from subcutaneous fat the different kinds of proteins it might secrete into the bloodstream that might have a beneficial effect.”

“Even though fat has been around forever and has been studied for many years, there are still a lot of things we don’t understand,” Kahn said.

—Staff writer Lingbo Li can be reached at lingboli@fas.harvard.edu.