America’s battle of the bulge has picked up increased urgency, thanks to two separate studies on how obesity affects testosterone levels.

Girls and Testosterone: During early puberty, obese females’ levels of the sex hormone testosterone ranged from two to nine times higher than those of normal-weight girls, concluded one study. Too much testosterone in females can stimulate excess hair growth, increase the risk for diabetes and cause reproductive problems such as disrupted menstrual cycles and infertility.

Middle-Aged and Older Men: Another study found that males whose weight grew from normal to obese over the trial’s 15 years of observation experienced a decline in testosterone equal to an additional 10 years of aging. Negative effects of testosterone loss for men include higher diabetes rates, reduced bone and muscle mass and sexual performance problems. The study shows that while age deflates testosterone levels, men may be able to minimize how much of the hormone they lose—and control the negative effects of that loss—by managing their weight.

Are You At Risk? Obesity means having a body mass index (BMI) of 30 or greater. That’s the equivalent of a  4-foot-10-inch girl weighing 145 pounds or more, or a 5-foot-10-inch man who is 210 pounds or above. To calculate your BMI, go to