Gender differences in weight loss

As men and women age, fat pads their bodies in different places. Men typically put so-called visceral fat around their middles, but women tend to cushion their hips and thighs with extra fat. An animal study now suggests that men and women might lose weight differently, too.

Deborah J. Clegg of the University of Cincinnati Medical Center and her colleagues report that female rats ate less and lost weight after injections of leptin, a hormone linked to appetite control. This response was not apparent for male rats. In contrast, the males ate less and lost weight after injections of insulin, but the females didn’t. Females with their ovaries removed responded more as males did to the two hormones.

Sex differences are likely to affect potential new weight-loss drugs, Clegg says. “If you’re looking for a drug to reduce obesity, you need to take this into account,” she says. She reported the findings last month in San Francisco at the annual meeting of the American Diabetes Association. Recent studies have also shown gender differences in brain responses to hunger (SN: 7/6/02, p. 4: His-and-Her Hunger Pangs: Gender affects the brain’s response to food).