Obesity and Sexuality

Obesity and sexuality in men and women: Myths, misconceptions, and the data

Department of Obstetrics and Gynecology, Albert Einstein College of Medicine, Bronx, New York

Clinicians may not fully appreciate the extent to which obesity does—and does not—affect sexual function and frequency of sexual activity. This article will review reports in the medical literature that provide insights into the sexual health of obese patients to better enable clinicians to address patient needs.

This is of particular importance because 32% of US adults currently fit the criteria for obesity¹; by 2015, 41% likely will be obese.² Medical consequences range from an increased risk of chronic disease³ to effects on reproductive health and fertility.⁴

Overweight and obese individuals tend to marry or cohabit with individuals of similar weight^5,6; therefore, issues of sexual health and obesity may affect both partners. Still, gender-specific differences concerning the effects of obesity on sexuality and sexual function have been observed.

Obesity, sexuality, and sexual activity in women

Research suggests a complex relationship among obesity and sexuality and sexual function in women.

Conflicting reports in the literature

Although some surveys of college students have emphasized weight-related stigma,⁷ studies of sexual function in women with large body mass provide conflicting results. An often-quoted report evaluated subject recall and a diary of vaginal intercourse frequency. It suggested a significant negative correlation between hip and waist size and coital frequency,⁸ as well as more frequent masturbation in large-bodied individuals. This fueled speculation that individuals who have large body mass may not find partners as easily as their leaner counterparts.

A small study of 29 hirsute women⁹ (mean body mass index [BMI], 29.6 kg/m²) reported lower indices of sexual desire and “body esteem” compared with normal-weight women. Such data from small case control studies has potential for bias because of criteria for control group selection and limited ability to control for potential confounders.

Positional difficulties during coitus affect morbidly obese patients. While this issue has been a subject of interest in literature regarding human sexual behavior,¹⁰ medical journals seldom mention it. Most data reflect case reports, although one study (n = 82) evaluated interviews with morbidly obese women (mean BMI, 42.8 kg/m²), revealing that 11% cited “physical problems” as the foremost difficulty when engaging in sexual intercourse.¹¹

Findings from larger trials

In contrast, several recent reports from larger studies showed no significant effects of BMI on sexual activity. An analysis of 626 infertile women with polycystic ovary syndrome revealed no BMI-based difference in terms of the frequency of timed sexual intercourse for procreative purposes.¹² However, this study represented a secondary analysis of data collected for fertility intervention.

Recently, investigators used a cross-sectional database from the 2002 National Survey of Family Growth¹³ that included 6690 women between the ages of 15 and 44 years. A study goal was to determine whether an increased BMI was associated with an altered pattern of sexual behavior. The researchers used audio self-interviewing software as well as self-reported weight and height. The mean BMI for the study population was 25.8 kg/m²; 54% of participants were classified as normal, 25% as overweight, and 21% as obese.

The descriptors used to indicate sexual behavior included self-reported information on sexual orientation, prior heterosexual and homosexual intercourse, frequency of sexual activity over the past month, age of first sexual activity, and number of lifetime and current sexual partners. A total of 90.5% participants self-identified as heterosexual and 9.5% as homosexual, bisexual or “something else.” In assessing parameters describing sexual behavior, no appreciable differences were noted in frequency of sexual activity among the 3 body mass groups (TABLE 1).

Surprising findings. Compared with normal-weight women, both obese and overweight women had a statistically significantly higher likelihood of ever having had heterosexual intercourse (77% and 56%, respectively). This single positive finding of difference was unexpected and in contrast to the absence of difference in reported sexual orientation. The investigators did not evaluate women with a lower-than-normal BMI as a separate group; however, some reports suggest decreased sexuality in severely underweight individuals.¹⁴ Nonetheless, the main conclusion of this well-designed investigation should not be ignored: Obese and overweight women do not report decreased frequency of sexual encounters as compared with their lean counterparts.

Most characteristics of sexual behavior differ little between women of different body mass: Cross-sectional study of 6990 US women ages 15 to 44

Sexual abuse, obesity, and weight loss

History of sexual abuse should be considered in any analysis, as it has been postulated to be a risk for developing obesity as a so-called “adaptive function.”¹⁵ Additionally, patient history may affect both surgical weight loss and sexuality. The literature concerning bariatric surgery literature suggests 2 potential issues. First, women with a sexual abuse history may lose less weight than expected for the type of surgery and baseline weight.¹⁶ Second, heightened vulnerability associated with self-perceived sexual attractiveness may lead to psychological issues.¹⁷ Sexual abuse victims have been reported to experience more postoperative depressive symptoms than do their counterparts without such history.¹⁸

The impact of significant weight loss on sexuality

Few studies have evaluated the effects of weight loss on female sexuality; most recent reports have surveyed women who have undergone bariatric surgery for morbid obesity. The overwhelmingly positive health benefits of such surgery include normalization of fertility and reproductive parameters, such as increased frequency of ovulation and improved menstrual regularity.

Most available data describing the effects of massive weight loss on sexuality derive from relatively small studies. In a study with historical controls by Kinzl et al, interviews with patients (n = 82) revealed that 63% reported an improvement in enjoyment from sexual activities.¹¹ To control for time-related factors, a recent long-term study followed 106 individuals postoperatively for up to 40 months.¹⁹ Women who had a history of sexual abuse and those who had no such history lost similar amounts of weight. Although results of this study are encouraging, the relatively small sample size suggests that the finding of “no difference” may be subject to type II error; a larger population is likely needed to confirm or refute the possible effect of history of sexual abuse on outcomes after bariatric surgery.

Sexual health in men with obesity

Most of the literature of the effects of obesity on male sexuality focuses on the increased prevalence of impotence and erectile dysfunction (ED): Reports suggest that obese men may have up to a 30% higher risk of ED, a phenomenon linked to endothelial dysfunction potentially shared by both health factors.²⁰ In a study of 22,086 US men, obesity was associated with a relative increase of up to 90% in the development of new cases of ED over 14 years of follow-up.²¹ Sparse data assess the effects of large body mass on sexuality in obese men who do not experience ED; at least one study reports less sexual desire in morbidly obese men.²²

Impact of weight loss on sexual function in men

Dramatic effects of moderate weight loss on sexual function in obese men have been demonstrated in a randomized controlled trial. The investigators evaluated nonsurgical weight loss using nutritional counseling and exercise in 110 obese men diagnosed with ED.²³ After 2 years of intensive lifestyle changes, men in the intervention group had lost a moderate amount of weight and had significantly improved ED (TABLE 2). Biological plausibility of these encouraging results is further supported by several studies documenting weight loss effects, such as recovery of obesity-related decreased testosterone and an overall improvement in male reproductive hormone dynamics.^24-27 Perhaps most important is the fact that the improvement in sexual functioning is demonstrated with only moderate weight loss using conservative measures such as diet and increased physical activity.

Randomized controlled trial of erectile dysfunction in obese males: Effects of moderate weight loss after 2 years of lifestyle changes

Conclusion

In summary, data on sexuality of obese individuals suggest that frequency of sexual activity is similar to that of normal-weight individuals.

With the rising prevalence of obesity, women’s healthcare providers should become proficient in dealing with issues relating to contraceptive services, sexually transmitted disease prevention, and preconception counseling for patients with large body mass. Women with a history of sexual abuse may represent special challenges when presenting for preoperative evaluation for weight loss surgery.

In obese men, ED is a major cause of sexual dissatisfaction. Moderate weight loss in obese men results in improvement of erectile dysfunction.

Sexuality, Reproduction & Menopause ©2010 Quadrant HealthCom Inc.