Obesity is associated with a variety of adverse sexual and reproductive health outcomes, according to a national study of French women and men.1 For example, obese women aged 18–29 were more likely than their normal-weight peers to have ever had an unintended pregnancy (odds ratio, 4.3) and to have had an abortion in the past five years (3.7). Among 18–29-year-olds who did not want to get pregnant, obese women were less likely than normal-weight women to have used oral contraceptives the last time they had sex (0.3) and more likely to have relied on withdrawal (8.5). In addition, among some subgroups of men, obesity was associated with having had an STD in the past five years and with never having used a condom in the past year.

The findings come from the Contexte de la Sexualité en France, a survey of a randomly selected, population-based sample of French men and women aged 18–69. Conducted by telephone in 2005–2006, the survey included questions on a range of sexual and reproductive characteristics, behaviors and outcomes. The current analysis focused on 5,535 women and 4,635 men who completed a detailed version of the survey that included questions on weight and height. Respondents were classified as underweight if their body mass index was less than 18.5, normal-weight if it was at least 18.5 but less than 25, overweight if it was at least 25 but less than 30, and obese if it was 30 or greater. The researchers used logistic regression to examine associations between body mass index and sexual and reproductive measures; analyses were conducted separately for women and men, and some were restricted to respondents from particular age-groups (-generally 18–29 and 30–49).

Nearly two-thirds of female participants (63%) were normal-weight, but almost a third were overweight (21%) or obese (9%). Only 54% of men were normal-weight; most of the rest were overweight (35%) or obese (9%). Obese respondents tended to be older and less educated than those of normal weight. After adjustment for age, obesity was associated with having a chronic disease among members of both sexes (odds ratio, 1.9 for each); it was associated with being limited in one’s daily activities among women (2.0).

In analyses that adjusted for age, education, chronic disease, couple status and limitations on activities, obese women were less likely than their normal-weight counterparts to have had a sexual partner in the past 12 months (odds ratio, 0.7), although they were just as likely as normal-weight women to be living with a partner. In addition, they had twice the odds of normal-weight women of reporting that sexuality was not important for their “personal life balance.” Among women aged 18–29, obese respondents were more likely than normal-weight respondents to have met a partner through the Internet (4.8). Overweight women did not differ from normal-weight women on these measures, however, and women’s sexual practices, frequency of intercourse and satisfaction with their sex life did not differ by body mass index.

Among men, sexual behaviors varied little by body mass index. The main exception was that both obese and overweight men were less likely than normal-weight men to have had multiple partners in the past year (odds ratios, 0.3 and 0.7, respectively).

None of the three assessed aspects of female sexual dysfunction—painful intercourse, lack of sexual desire and arousal dysfunction—was related to weight status. However, male sexual dysfunction was strongly associated with body mass index: Underweight men were more likely than normal-weight men to report premature ejaculation (odds ratio, 3.8) and lack of sexual desire (11.5), while overweight and obese men had elevated odds of erectile dysfunction (2.7 and 2.6, respectively).

Substantial differences between obese and normal-weight women were apparent on key measures of reproductive health, particularly among 18–29-year-olds. In these younger women, obese respondents were more likely than their normal-weight peers to have ever had an unplanned pregnancy (odds ratio, 4.3) or to have had an abortion in the past five years (3.7). In addition, those who were sexually active had reduced odds of having consulted a doctor about contraceptives in the past year (0.4) or, if they did not want to get pregnant, having used oral contraceptives at last intercourse (0.3); instead, they had an elevated likelihood of having used withdrawal the last time they had sex (8.5). Although some of these differences did not hold for 30–49-year-olds, obese women in this age-group were more likely than normal-weight women to have had an abortion in the past five years (2.0) and less likely to have seen a doctor for contraceptives in the past year (0.4). Being overweight was associated with only one adverse outcome related to contraception or reproduction: nonuse of condoms among women in both age-groups who had had more than one partner in the past year (3.4–3.8). In general, as body mass index increased among women younger than 30, their use of oral contraceptives and condoms declined and their use of withdrawal increased.

Obesity was also associated with adverse outcomes in men. Among those aged 18–29, the odds of having had an STD in the past five years were greater among obese than normal-weight men (odds ratio, 11.8). Moreover, obesity was associated with greatly reduced odds of condom use in the past year among men aged 30–49 who had had more than one partner (0.1).

The researchers note that the study’s limitations include its reliance on self-reported data and its focus on heterosexual relationships. Nonetheless, the findings underscore the need for health care professionals to provide all women, regardless of weight, with tailored sexual and reproductive health care. “Any temptation to think that obese women are less sexually active [than other women] and therefore less in need of effective methods of contraception is clearly without foundation,” the investigators emphasize. They add that although sexuality and body weight are sensitive topics, obese individuals “will certainly benefit from tactful guidance and advice.”—P. Doskoch