Objectives: Reduced sexual quality of life is a frequently reported yet rarely studied consequence of obesity. The objectives of this study were to 1) examine the prevalence of sexual quality-of-life difficulties in obese individuals and 2) investigate the association between sexual quality of life and BMI class, sex, and obesity treatment—seeking status.
Research Methods and Procedures: Subjects consisted of 1) 500 participants in an intensive residential program for weight loss and lifestyle modification (BMI = 41.3 kg/m2), 2) 372 patients evaluated for gastric bypass surgery (BMI = 47.1 kg/m2), and 3) 286 obese control subjects not seeking weight loss treatment (BMI = 43.6 kg/m2). Participants completed the Impact of Weight on Quality of Life-Lite, a measure of weight-related quality of life. Responses to the four Sexual Life items (assessing enjoyment, desire, performance, and avoidance) were analyzed by BMI, sex, and group.
Results: Higher BMI was associated with greater impairments in sexual quality of life. Obese women reported more impairment in sexual quality of life than obese men for three of four items. Gastric bypass surgery candidates reported more impairment in sexual quality of life than residential patients and controls for most items. In general, residential patients reported levels of impairment greater than or equal to controls.
Discussion: Obesity is associated with lack of enjoyment of sexual activity, lack of sexual desire, difficulties with sexual performance, and avoidance of sexual encounters. Sexual quality of life is most impaired for women, individuals with Class III obesity, and patients seeking gastric bypass surgery.
In addition to its medical consequences (1, 2, 3, 4), obesity has been linked to impairments in health-related quality of life, including reduced physical functioning, psychosocial functioning, and emotional well being (5, 6, 7, 8). Reduced quality of life may be as serious a consequence of obesity as are its adverse effects on morbidity and mortality (9).
Our clinical experience suggests that sexual dissatisfaction and/or sexual difficulties are not uncommon among our obese patients. Only a few research studies have examined the relationship between obesity and sexual quality of life. In men, obesity has been associated with lower sexual satisfaction (10), increased erectile dysfunction (11, 12), and penile vascular impairment (13). Less is known about obesity and sexual quality of life in women. One study (10) reported no differences in sexual satisfaction between obese and non-obese women. However, in the 18- to 49-year-old cohort, obese women (and men) reported a greater decrease in sexual desire over the preceding 5 years compared with normal-weight individuals.
The limited numbers of studies on sexual quality of life in obesity, along with anecdotal reports of sexual dissatisfaction/dysfunction by obese patients, suggest that this is an area in need of further study. The objectives of this study were to 1) examine the prevalence of sexual quality-of-life difficulties in obese individuals and 2) investigate the association between sexual quality of life and BMI class, sex, and obesity treatment—seeking status.
Research Methods and Procedures
The sample for this study consisted of obese (BMI ≥ 30 kg/m2) adult (age ≥ 18 years) individuals from three different groups: 1) 500 participants in an intensive residential program for weight loss and lifestyle modification (14); 2) 372 patients evaluated for gastric bypass as part of the Utah Obesity Study (15); and 3) 286 individuals from a control group in the Utah Obesity Study who were randomly chosen from a population of severely obese participants but who were not seeking gastric bypass surgery (15). Only those participants who completed the four Sexual Life items on the Impact of Weight on Quality of Life-Lite questionnaire (IWQOL-Lite)1 (16, 17) were included in the current sample.
On initial evaluation for their respective programs/studies, participants’ heights and weights were obtained by the clinic/study personnel. BMI was calculated as kilograms per meters squared. BMI was categorized as Class I obesity = BMI of 30 to 34.9 kg/m2, Class II obesity = BMI of 35 to 39.9 kg/m2, Class III obesity = BMI of 40+ kg/m2 (18). Participants also completed questionnaires that included demographic information (age, sex, and ethnicity) and the IWQOL-Lite.
The IWQOL-Lite is a reliable and valid self-report measure of weight-related quality of life (16, 17, 19, 20). The IWQOL-Lite consists of 31 items that begin with the phrase, “Because of my weight …” Each item has five response options, ranging from 1) “Never true” to 5) “Always true.” The IWQOL-Lite provides scores in five domains (Physical Function, Self-Esteem, Sexual Life, Public Distress, and Work) along with a total score. For the purpose of this study, only responses to individual items from the Sexual Life scale were analyzed. The Sexual Life scale consists of four items that assess 1) lack of enjoyment of sexual activity, 2) lack of sexual desire, 3) difficulty with sexual performance, and 4) avoidance of sexual encounters—all items specifically attributed to one's weight.
Separate two-way ANOVAs with Tukey's honestly significant difference (HSD) post hoc comparisons (21) were used to compare responses to the four Sexual Life items across BMI categories (Class I, II, and III obesity) and sex. Partial η2 values were calculated to determine the proportion of unique variance accounted for by each factor.
Given previous findings of differences between men and women on IWQOL-Lite scores (22), as well as the sex differences obtained in the current samples, all of the analyses described below were conducted separately by sex. The three participant groups were compared on BMI and age using ANOVA with Tukey's HSD post hoc comparisons and on ethnicity using the χ2 test. Responses to each of the four IWQOL-Lite Sexual Life items were tabulated by group and sex. Finally, analysis of covariance was used to compare responses to each of the IWQOL-Lite Sexual Life items by group and sex, controlling for BMI and age. Post hoc comparisons among groups were based on covariate-adjusted Bonferroni-corrected contrasts. Again, η2 values were calculated to determine the proportion of unique variance accounted for by group differences.
Demographic and Weight Characteristics
Table 1 presents demographic characteristics and BMI by group and sex. Age was significantly different among groups for both women (F = 30.00; df = 2, 797; p < 0.001) and men (F = 6.68; df = 2, 355; p = 0.001). For women, control group participants were significantly older than residential program participants, who were, in turn, significantly older than gastric bypass patients. For men, residential program participants were significantly older than gastric bypass patients.
Table 1. . Demographic characteristics and BMI by group and sex
|Women||Residential program||277||46.0 (13.5) Range = 18 to 82||40.1 (8.6) Range = 30.0 to 101.4||254 (91.7%)|
| ||Gastric bypass||312||41.0 (10.2) Range = 19 to 63||46.5 (7.3) Range = 32.9 to 71.8||276 (88.4%)|
| ||Controls||211||48.8 (11.0) Range = 18 to 72||43.3 (6.1) Range = 33.3 to 70.9||204 (96.7%)|
|Men||Residential program||223||51.0 (13.2) Range = 20 to 82||42.8 (11.0) Range = 30.1 to 86.0||205 (91.9%)|
| ||Gastric bypass||60||44.7 (11.2) Range = 18 to 66||50.3 (9.3) Range = 37.2 to 84.3||54 (90.0%)|
| ||Controls||75||48.3 (9.9) Range = 25 to 65||44.3 (7.1) Range = 34.1 to 69.4||73 (97.3%)|
BMI was also significantly different among groups for both women (F = 52.83; df = 2, 797; p < 0.001) and men (F = 13.09; df = 2, 355; p = 0.001). For women, gastric bypass patients had significantly higher BMI than control group participants, who, in turn, had significantly higher BMI than residential treatment participants. For men, gastric bypass patients had significantly higher BMI than both control group and residential program participants.
Although the majority of participants were white, the proportion of white participants differed significantly among groups for women (χ2 = 11.24, df = 2, p = 0.004), with the highest rates in the controls and the lowest rates in the gastric bypass candidates. There were no differences in the proportion of white participants among groups for men (χ2 = 3.24, df = 2, p = 0.198).
Comparisons across BMI Categories and Sex
Table 2 presents Sexual Life item responses by BMI category (Class I, II, and III obesity) and sex. Significant differences by BMI group were obtained for all Sexual Life items except sexual desire. Participants in the Class III obesity group reported less sexual enjoyment, more difficulty with sexual performance, and greater avoidance of sexual encounters in comparison with the other two BMI groups. For two items (enjoyment, performance), the Class II group reported greater impairment than the Class I group; for the remaining item (avoidance), there were no significant differences between the Class I and Class II groups. Women reported greater impairments than men on sexual enjoyment, desire, and avoidance of sexual encounters, but did not differ in terms of difficulties with sexual performance. None of the BMI group-by-sex interactions approached significance (p values ranging from 0.240 to 0.766). For three of the four items (enjoyment, desire, avoidance), sex accounted for a greater portion of the criterion variance than BMI category, whereas for sexual performance, BMI category accounted for a greater portion of the variance.
Table 2. . IWQOL-Lite Sexual Life responses by BMI category
|Do not enjoy sexual activity|| || || || || || || |
| Women||2.34 ± 1.36||2.59 ± 1.33||3.00 ± 1.46||BMI: 11.35||<0.001||0.019||III>II>I|
| Men||1.68 ± 1.02||1.93 ± 1.14||2.11 ± 1.36||Sex: 53.02||<0.001||0.044||F > M|
|Have little sexual desire|| || || || || || || |
| Women||2.89 ± 1.32||2.72 ± 1.31||3.09 ± 1.41||BMI: 2.22||0.109||0.004|| |
| Men||2.29 ± 1.22||2.41 ± 1.23||2.43 ± 1.27||Sex: 27.50||<0.001||0.023||F > M|
|Difficulty with sexual performance|| || || || || || || |
| Women||2.31 ± 1.37||2.55 ± 1.36||3.08 ± 1.41||BMI: 17.67||<0.001||0.030||III>II>I|
| Men||2.17 ± 1.05||2.58 ± 1.25||2.78 ± 1.40||Sex: 1.86||0.173||0.002|| |
|Avoid sexual encounters|| || || || || || || |
| Women||2.67 ± 1.46||2.72 ± 1.43||3.02 ± 1.52||BMI: 6.12||0.002||0.011||III>II,I|
| Men||1.88 ± 0.98||2.15 ± 1.12||2.35 ± 1.38||Sex: 40.01||<0.001||0.034||F > M|
Sexual Quality-of-life Item Responses by Group Separately by Sex
Table 3 presents responses to each of the four IWQOL-Lite Sexual Life items by group separately for women and men. Across all four items, obese women reported higher frequencies of impairment than obese men. Furthermore, women reported each of these items with approximately equal frequency, whereas men reported some items (e.g., sexual desire and sexual performance) more than others. Female gastric bypass candidates reported much higher frequencies of sexual difficulties than either female residential program participants or controls.
Table 3. . IWQOL-Lite Sexual Life responses by group and sex
|Do not enjoy sexual activity|| || || || |
| ||Residential program||63.9%||19.1%||17.0%|
| ||Gastric bypass||20.8%||27.9%||51.3%|
| ||Obese controls||49.8%||24.2%||26.1%|
| ||Residential program||80.7%||9.4%||9.9%|
| ||Gastric bypass||35.0%||26.7%||38.3%|
| ||Obese controls||72.0%||18.7%||9.3%|
|Have little sexual desire|| || || || |
| ||Residential program||45.5%||23.8%||30.7%|
| ||Gastric bypass||22.4%||25.6%||51.9%|
| ||Obese controls||54.0%||20.4%||25.6%|
| ||Residential program||54.3%||22.0%||23.8%|
| ||Gastric bypass||38.3%||21.7%||40.0%|
| ||Obese controls||76.0%||12.0%||12.0%|
|Difficulty with sexual performance|| || || || |
| ||Residential program||61.4%||18.1%||20.6%|
| ||Gastric bypass||20.8%||24.0%||55.1%|
| ||Obese controls||53.6%||24.2%||22.3%|
| ||Residential program||53.4%||22.0%||24.7%|
| ||Gastric bypass||26.7%||21.7%||51.7%|
| ||Obese controls||61.3%||24.0%||14.7%|
|Avoid sexual encounters|| || || || |
| ||Residential program||49.5%||18.1%||32.5%|
| ||Gastric bypass||32.7%||17.0%||50.3%|
| ||Obese controls||58.3%||18.0%||23.7%|
| ||Residential program||63.7%||17.9%||18.4%|
| ||Gastric bypass||45.0%||25.0%||30.0%|
| ||Obese controls||82.7%||9.3%||8.0%|
Approximately one third of women (32.8% to 37.6%) reported that they usually or always did not enjoy sexual activity, had little sexual desire, experienced difficulty with sexual performance, and avoided sexual encounters because of their weight. Approximately one half of obese women (54.7% to 61.2%) reported difficulty with these aspects of sexual quality of life at least some of the time.
For obese men, the most commonly reported sexual concern related to weight was difficulty with sexual performance (nearly 50% reported problems at least sometimes), followed by lack of sexual desire (just >40% reported problems at least some of the time). Approximately 15% of obese men (14.5% to 18.2%) reported usually or always experiencing difficulties with sexual enjoyment and avoidance of sexual encounters. However, more than two thirds of men (71.2%) responded “never” or “rarely” to the item, “Because of my weight I do not enjoy sexual activity.” Consistent with the findings for women, male gastric bypass candidates reported much higher rates of difficulties in all four aspects of sexual quality of life than the residential program participants or controls.
Comparisons among Treatment-seeking Groups
Table 4 presents responses for women to the four IWQOL-Lite Sexual Life items by treatment-seeking group, controlling for differences in BMI and age. Significant differences were found among groups for all four items, accounting for between 7% (avoidance) and 14% (enjoyment) of the criterion variance. In all cases, female gastric bypass candidates had scores indicating significantly more impairment than the remaining groups. With one exception (sexual enjoyment), women in the residential program reported levels of impairment greater than or equal to female control subjects.
Table 4. . IWQOL-Lite Sexual Life responses by group for women
|Enjoyment||2.22 ± 1.31||3.53 ± 1.31||2.57 ± 1.34||66.49||<0.001||0.143||GB > C > RP|
|Desire||2.79 ± 1.34||3.50 ± 1.30||2.45 ± 1.34||39.59||<0.001||0.091||GB > RP > C|
|Performance||2.44 ± 1.33||3.52 ± 1.29||2.44 ± 1.31||57.22||<0.001||0.126||GB > RP,C|
|Avoidance||2.74 ± 1.47||3.40 ± 1.47||2.39 ± 1.36||29.97||<0.001||0.070||GB > RP > C|
Data for men are presented in Table 5. Significant differences were found among treatment-seeking groups in all four aspects of sexual quality of life, accounting for between 6% (avoidance) and 12% (enjoyment) of the criterion variance. For items assessing lack of sexual enjoyment and difficulty with sexual performance, men in the gastric bypass group reported more problems than either men in the residential program or male control subjects, who did not differ from each other. In contrast, for items assessing desire and avoidance of sexual encounters, men in the gastric bypass group and men in the residential program did not differ from each other, but reported more impairment than male control subjects.
Table 5. . IWQOL-Lite Sexual Life responses by group for men
|Enjoyment||1.76 ± 1.09||2.97 ± 1.27||1.92 ± 1.09||25.72||<0.001||0.127||GB > C,RP|
|Desire||2.45 ± 1.21||2.87 ± 1.34||1.88 ± 1.25||12.12||<0.001||0.064||GB, RP > C|
|Performance||2.58 ± 1.31||3.29 ± 1.38||2.26 ± 1.11||11.50||<0.001||0.061||GB > RP, C|
|Avoidance||2.29 ± 1.24||2.64 ± 1.41||1.72 ± 1.02||10.61||<0.001||0.057||GB, RP > C|
This is a study of the relationship between obesity and sexual quality of life. This is a greatly understudied research area that may have important implications for understanding and treating obese persons. With the increasing prevalence of obesity, sexual issues are likely affecting more people than usually realized. The major findings in this study are that 1) obese individuals report a high frequency of sexual difficulties attributed to their weight (lack of sexual enjoyment, lack of sexual desire, difficulty with sexual performance, and avoidance of sexual encounters); 2) higher BMI is associated with greater impairments in sexual quality of life; 3) sexual quality of life is more impaired for obese women than for obese men; and 4) gastric bypass candidates report greater impairment in sexual quality of life than other obese individuals.
The high rate of sexual difficulties experienced by subjects in this study is consistent with previous findings of reduced sex drive and sexual satisfaction (23), as well as negative appearance evaluation (24), in obese individuals seeking weight loss treatment. A population study of sexual dysfunction in the United States has reported prevalence rates of 7% to 22% for women (sexual pain, arousal problems, and low desire) and 5% to 21% for men (erectile dysfunction, low desire, and premature ejaculation) (25). In contrast, this study of obese persons, albeit not a population study, found much higher rates of impairment in sexual quality of life, particularly for individuals seeking gastric bypass surgery. Although the population study did not examine subjects by BMI, the authors noted that sexual dysfunction was associated with poorer physical and emotional health.
Our finding of greater sexual impairment in women than in men (with the exception of difficulties with sexual performance) is also consistent with previous reports of poorer body image (26), higher prevalence of sexual difficulties (25), reduced health-related quality of life (27, 28), and decreased weight-related quality of life (22) in women compared with men. Likewise, our finding that obese persons seeking gastric bypass surgery report the greatest impairments in sexual quality of life and obese community subjects the least is consistent with previous research on differences in weight-related quality of life across subgroups of obese persons differing in treatment status (22). This finding is also consistent with research reporting differences in prevalence of sexual difficulties between patients in primary care settings vs. general community samples (29).
The results of this study may have implications for clinicians who treat patients who are obese. Obese persons commonly experience stigmatization, discrimination, and prejudice because of their weight (30, 31). Additionally, and perhaps related to the above, many obese persons have a negative body image (24). Thus, the combination of social stigmatization/prejudice and a negative body image may present social and psychological barriers to having sexual needs met. It is likely that many obese persons who experience diminished sexual quality of life and/or negative body image may wish to discuss these issues with their health care providers. Thus, providers need to create an atmosphere of acceptance and willingness to discuss these issues with their patients. This may be achieved simply by asking patients a few questions during initial screening, listening to patients’ concerns with empathy, and putting the concerns into perspective by describing their prevalence in this population (i.e., “normalizing” the concerns). It may also be useful for health care providers to highlight the potential benefits that weight loss and lifestyle change may confer on improved sexual quality of life (23, 32, 33, 34, 35, 36). When needed, appropriate referrals and treatments should be recommended—e.g., psychotherapy for body image/self-esteem issues and medical evaluation and/or treatment for sexual performance issues. Because impairment in sexual quality of life is greatest for women, individuals with Class III obesity, and patients seeking gastric bypass surgery, providers should be particularly mindful of the potential for sexual concerns in these patients.
One of the limitations of this study is that we assessed sexual quality of life using a four-item scale from a measure of weight-related quality of life. We recognize that sexual quality of life is a rich and multifactorial construct (including arousal, desire, satisfaction, physical functioning, beliefs and values, comfort with sexual and emotional intimacy, body image, and self-esteem), and our findings address only the impact attributed to one's weight on sexual enjoyment, sexual desire, difficulty with sexual performance, and avoidance of sexual encounters. Given the paucity of research in this important area and the obvious relevance of this information for clinicians treating obese persons, more research is needed. Fruitful future research directions may include longitudinal studies and in-depth qualitative research using instruments that are specifically designed to assess sexual functioning from a multidimensional perspective and that are applicable to both obese and non-obese subjects (37, 38, 39, 40). Additionally, research is needed on the role of weight loss in improving sexual quality of life. Current research on this topic is limited and includes men only. In one study, about one third of obese men with erectile dysfunction reported improved sexual function after weight loss and lifestyle changes (33). In another study, obese men (not necessarily with erectile dysfunction) who lost weight showed increased serum testosterone but no significant improvement in sexual function scores (41).
Because of our study's cross-sectional design, we are limited in the causal conclusions we are able to draw with respect to the relationship between obesity and sexual quality of life. Additionally, because of the relatively small number of men in the gastric bypass and control groups, there may be limited statistical power to detect differences among the groups. Finally, geographic differences may have influenced our findings (i.e., gastric bypass patients and control subjects were from Utah, whereas residential subjects came from numerous locations in the United States and abroad).
In summary, we found that obese individuals report a high frequency of sexual difficulties attributed to their weight and that sexual quality of life is particularly impaired for obese women, gastric bypass candidates, and individuals with Class III obesity. If we are to understand more fully the needs of our obese patients, more comprehensive assessment is needed to address the impact of weight on sexual quality of life, body image, and other important aspects of overall quality of life.
Portions of this paper were presented in a poster session at the NAASO 2004 meeting in Las Vegas. Dr. Østbye is partially funded by National Institute of Diabetes and Digestive and Kidney Diseases grant number DK-64, 986. Data provided by the Utah Obesity Study was funded by National Institute of Diabetes and Digestive and Kidney Diseases grant number DK-55, 006 and by Public Health Service research grant number M01-RR00064 from the National Center for Research Resources.