A large weight gain can certainly send libidos through the floor, experts say but not in the way you might think.
When Kathy, an inventory planner from Illinois, gained weight, it hurt her relationship and sex life significantly especially because she knew her younger boyfriend "has a preference for very thin women." Even though he never said anything about her weight gain, "I no longer wanted to be intimate with him," she said. "I felt like a house how could he possibly be physically attracted to me?"
Little is as it seems when it comes to the intersection of obesity and sexuality, according to Dr. David Sarwer of the University of Pennsylvania Medical School, including the assumption thinness is always sexy and fatness is not.
Although couples frequently report having sex less often when one partner gains a significant amount of weight, it's often not because the other partner's libido has decreased, but because people who gain weight can become more dissatisfied with their bodies, Sarwer said. "If you're unhappy with your physical appearance, you may be uncomfortable having someone see and touch your body."
"An overweight person often feels an overpowering shame about their body," he added.
A Strain on Marriage
For Deborah and Tim from Oklahoma (they asked that their last names not be used), sex has been difficult since Deborah gained about 100 pounds a few years ago; she now weighs about 290. Her libido has flagged, and physical problems with her back and legs exacerbated by her weight have made intercourse extremely uncomfortable.
"I don't see myself as sexually attractive," she said, but her husband "is just as interested in my body as he was when we married. I don't know why. It does put a bit of a strain on things when he is wanting to do something and I use the old standbys: I'm tired, etc. I usually am but it is because of all the weight."
The physical symptoms of obesity can be just as sexually debilitating as the psychological burden. In addition to back pain and circulation problems, conditions like diabetes and hypertension that are more common in overweight people can cause problems with arousal as can the drugs that treat them.
According to researchers at Japan's Kurobe City Hospital, the high insulin levels caused by obesity can boost the amount of sex-hormone-binding globulin, which effectively mops up the testosterone and estrogen that are essential to making love.
The large-scale Massachusetts Aging Study found that obese men were at substantially greater risk for impotence.
Thinner Isn't Always Better
When the weight disappears, sex should get better, right?
Not so, according to Dr. Gary Foster, clinical director of University of Pennsylvania's Weight and Eating Disorder Program. He says one partner's loss of excess weight can cause more problems than gaining the weight did in the first place especially "if body weight has served a psychological function in the marriage."
"Say a woman is overweight and her husband is not," he said. "If the woman loses 40 pounds, now she's noticed by other men who wouldn't have flirted with her before the couple is not usually ready to deal." The excess weight was serving as a ready-made defense against potential infidelity: take it away, and the marriage can be in trouble.
In extreme cases, Foster said, one partner can even sabotage the other's attempts to lose weight for fear the newly thin partner will leave: Great job losing 10 pounds, honey let's go get ice cream to celebrate.
Alternatively, one partner may use the excess weight as a defense against unwanted sexual advances from the mate. When that weight starts to come off, the "excuse" of obesity is no longer valid, and the couple is forced to confront the fact that their sex lives are still dysfunctional.
"A change in appearance only plays a small role in the dynamic of the relationship," Sarwer said. "A lot of persons daydream that losing weight will cause a Cinderella-like transformation in their bodies and relationships, but those are often unrealistic expectations."
Talking It Over
The best way for people to discuss weight changes with their partners whether it's on the plus or minus side of the ledger is to be upfront, honest and very, very careful about how they frame the issue, Foster said. It's important to emphasize that you are concerned about their health and the health of the relationship, but you're not about to walk out the door because of their weight.
"If you say 'your weight bothers me,' that can seem uncaring and unloving," he said. "It's important to distinguish your concern about weight from your concern about the person. If it's authentic, say, 'I'm concerned about your health. And I'm not proud to admit this, but it affects how I feel sexually."
"It's a tricky business, but you shouldn't" beat around the bush, he said.
Deborah and Tim have reached a point where they can compromise, with Tim agreeing "not to push as much." She's the only girl he's ever gone out with, he said, and because of their marriage he can't ever imagine cheating on her with someone else.
"When we got married, she weighed a lot less than she did now," he said. "But it didn't matter to me, because she's still herself, and that's what I look at whether she weighs 98 pounds or 500."