But cultural messages also continue to tell us that no one bigger than a size 6 should be singing the siren song of sexuality. Much like oil and water, being overweight and sexy just don't mix. For those already struggling with weight and image issues, that powerful message can easily throw a wet blanket on even the most active libido.

"Unfortunately, people are internalizing society's definition of what it takes to be involved in sex, particularly the body shape -- there are clearly societal biases out there that are influencing us on an individual level and not in a good way, " says Martin Binks, PhD, a clinical psychologist and director of behavioral health at Duke University's Diet and Fitness Center in Durham, N.C.

But it turns out that cultural messages aren't the whole story. New research suggests certain physical conditions that go along with obesity also affect sex drive, further dampening the desires of those who are overweight. The good news: You can make some changes to your body (and how you think about your body) to enhance your libido. You can:

• Lose a little weight, even 10 pounds, to stimulate sex hormones
• Eat more nutritious foods, which control cholesterol and blood sugar levels
• Key your workouts to getting blood flowing to the pelvic area
• Pick up a sexy novel and start reading
• Accept your body at any size
• Believe in your sensuality

How to begin? Start by identifying the physical and psychological obstacles that could be standing in your way to a fulfilling sex life.

How Too Much Weight Hampers Sex Drive

According to a recent study conducted by Binks and his colleagues at Duke, up to 30% of obese people seeking help controlling their weight indicate problems with sex drive, desire, performance, or all three. Often, the latest research shows, these problems can be traced to physical conditions that co-exist with obesity.

"Medical conditions such as high cholesterol and insulin resistance [an early indicator of type 2 diabetes] do have the ability to impact sexual performance, which in turn impacts desire, particularly in men," says Andrew McCollough, MD, director of sexual health and male infertility at NYU Medical Center in New York.

Because both conditions can cause the tiny arteries in the penis to shut down, particularly when vessel-clogging fatty deposits begin to form, McCollough says impotence or erectile dysfunction is often the result.

"A man who has problems having an erection is going to lose his desire for sex in not too long a time," says McCollough.

Men aren't alone with sex problems caused by poor blood flow. Research shows overweight women's sex drive and desire are affected by the same problem.

"We are beginning to see that the width of the blood vessels leading to the clitoris [the area of the vagina most closely related to sexual response] in women are affected by the same kind of blockages that impact blood flow to the penis," says Susan Kellogg, PhD, director of sexual medicine at the Pelvic and Sexual Health Institute of Graduate Hospital in Philadelphia.

When this happens, says Kellogg, a woman's body is far less responsive, and a drop in desire is not far behind.

Complicating matters further for both sexes: The more body fat you have, the higher your levels of a natural chemical known as SHBG (short for sex hormone binding globulin). It's aptly named because it binds to the sex hormone testosterone. Doctors theorize that the more testosterone that is bound to SHBG, the less there is available to stimulate desire.

Visit the WebMD Weight Loss Clinic

Simple Changes to Boost Your Sex Drive

What can you do to improve your physical conditioning for sex? Plenty. Experts say losing as few as 10 pounds can often free up testosterone and almost immediately give a boost to your love life.

Even better news. Making the same diet changes -- such as following a low-fat diet and eating lots of fruit and vegetables -- that help get blood sugar and cholesterol under control can also help turn your sex drive around -- even if you don't lose weight.

Says Binks, "I've noted that very often when patients start to take better care of themselves, they also report a substantial increase in their interest in sex -- I think participation in a healthy lifestyle really helps, even if you don't lose the extra pounds."

Also, Kellogg says exercises designed not for weight loss but to increase circulation to the genitals can make a big difference, particularly for women.

"Any activity that increases blood flow to the large muscle groups in the thighs, buttocks, and pelvis -- such as yoga, brisk walking, or cycling for 20 minutes three times a week -- is also going to bathe the genitals with better circulation," says Kellogg. The result, she says, is more lubrication, better arousal, and better orgasmic function. And ultimately a return of sexual desire.

Kellogg also tells WebMD that women might consider supplementing their sexy workout with a little light erotic reading for 20 minutes three times a week. The goal here: To focus attention back on sex and improve both drive and desire.

"There is nothing sexy about housework or PTA meetings or grocery shopping. If that's taking up all your thoughts, there is no room to think about sex, no matter what your shape or size," says Kellogg.

"Weight becomes less of an issue when a woman simply feels better and feels sexy," she says.

Think Sexy, and You'll Be Sexy

Which leads us to what may be happening in your head. For some people, getting physical problems under control is all it takes to fan the flames of desire. For others, it's still not quite enough.

Experts say that one of the biggest obstacles to enjoying sex at any size is a poor body image. They caution that the inability to accept your weight and your size can leave you sleeping single in a double bed.

"There is this idea out there that if you accept your body and your weight that it's somehow going to take away your motivation to change the way you look -- in a way, society almost tells us that you have to hate your body before you can improve it," says Binks.

This is the kind of attitude, he says, that frequently causes overweight folks to feel so self-conscious about how they look that desire is completely inhibited.

Psychologist and body-image expert Abby Aronowitz, PhD, agrees. "The epitome of sexuality is abandoning self-consciousness to experience the moment intensely. If one is fretting about this bulge or that bulge or how their butt looks from every angle, it's pretty difficult to enjoy the moment, much less be there for your partner," says Aronowitz, author of Your Final Diet .

While body image can hamper both men and women, experts agree that women feel the impact more. In fact, Kellogg reports that even women who have loving partners can still view themselves as sexually unattractive if their body image doesn't conform to the "norm."

"If a woman doesn't find herself to be sexually appealing, she will believe she is not sexually appealing to her partner, even if he tells her she is," says Kellogg.

Sexual Desire Still Missing? Get Help.

Although small changes in lifestyle along with some healthy "self-talk" can go a long way toward improving both drive and desire, if you still can't think of yourself as desirable, some professional image counseling may be in order.

"If you are someone who has very negative feelings about your body image, then getting treatment that works toward improving self-esteem will automatically be reflected in your desire for sex and your ability to achieve sexual fulfillment, regardless of your size," says Binks. The best place to start is often with your family doctor. But if you feel you need more specialized help, experts say, don't hesitate to turn to a counselor with expertise in body image and weight issues.

Above all, remember this: While studies show that up to 30% of overweight people have sexual difficulties, Binks points out that up to 70% of overweight people are doing just fine -- and you can, too.

The key, says Aronowitz, is this: "Don't buy into society's idea of the perfect sexual body, and do allow your own sexuality and sensuality to thrive inside the body you have."

By Colette Bouchez
Reviewed By Kathleen Zelman, MPH, RD, July 25, 2007.
Published March 25, 2005.
Medically updated July 25, 2007.

SOURCES: Martin Binks, PhD, clinical psychologist; director of behavioral health, Duke University Diet and Fitness Center, Durham, N.C. Andrew McCullough, MD, director of sexual health and male infertility, NYU Medical Center. Susan Kellogg, PhD, director of sexual medicine, Pelvic and Sexual Health Institute, Graduate Hospital, Philadelphia. Abby Aronowitz, PhD, clinical psychologist specializing in body image. Journal of Sex and Marital Therapy , 2000; vol 26: pp 191-208. Annual meeting of the North American Association for the Study of Obesity, Las Vegas, Nov. 14-18, 2004.