ACADEMIA — Body weight and sexual activity level are related in both men and women but in very different ways, according to two recent scientific studies.In a report published in the journal Obstetrics & Gynecology, Oregon State University researchers debunked the conventional notion that large women don’t have sex with men as often as their more svelte sisters. In fact, quite the opposite is true: Even obese women are sexually active, with 92-percent of the overweight members of the 7,000-member group participating in the study reporting regular intercourse. In contrast, only 87-percent of women in the “normal” weight range reported regular male-female activity.

“It’s totally unexpected,” Marie Harvey, the Oregon State University professor who co-authored the study, told Canada.com. She attributed the unexpectedness of the results to society’s “stereotype that men are attracted to slender women.”

Even more surprising: Overweight and normal-weight women reported no appreciable differences in age of first intercourse or number of partners even though thinner women often are perceived as more sexually empowered, Harvey noted.

She declined to speculate about reasons for women’s sexual activity levels, because the study didn’t attempt to assess subjective variables like presumed needs for emotional validation and satisfaction with sexual experiences. Others, however, have suggested overweight and obese women seek approval through sexual activity.

Previous studies have suggested a link between obesity and diminished libido. Harvey’s study called into that notion into question.

“I think what [the study] does tell us is that sexual beings come in [various] sizes, shapes and ages,” Harvey told Canada.com. “We should make no assumptions when we interact with different women.”

Men, on the other hand, have reason to worry when their waistlines expand. A separate study conducted by researchers at the University of Utah indicated a link between weight gain and hormonal changes that decrease sex drive and introduce performance issues.

“Previous studies have found that obesity is correlated to lower sperm count and can be associated with infertility, but we wanted to know if obesity was biologically associated with an unsatisfying sex life, and if so, could it be reversible,” Dr. Ahmad Hammoud, lead author of the study, noted in a prepared statement. “Our results show that the answer to both questions may be yes.”

The study’s subject comprised 64 obese men, some of whom underwent gastric-bypass surgery to lose weight. At the end of the two-year investigation, the men who reduced their body mass index reported increases in the quality of their sex lives, which the researchers attributed to a reduction in estradiol levels coupled with a simultaneous increase in testosterone.