Most published research on obesity and psychological trauma has focused on the relationship between adulthood obesity and childhood sexual abuse (CSA), in which there is an overall consensus that a small, positive correlation exists.^8–11 Little is known about the relationship between obesity and adulthood sexual abuse (ASA); further investigation is needed to understand how ASA influences adulthood obesity.

Some researchers have suggested theories as to why SA may contribute to obesity.^8,15 One theory proposes that obesity may be employed by female SA survivors as an adaptive strategy to avoid sex in relationships or to deter potential sexual predators. It is hypothesized that a higher body weight is maintained because the SA survivor does not want to be viewed as a sexual object.^8,15 In support of this theory, researchers have found that some women with SA histories have a barrier weight, where weight is gained to become less attractive or to have a different sized body than the one they had at the onset or time of sexual victimization. Some women with SA histories who begin to lose weight experience posttraumatic stress disorder (PTSD) symptoms as they approach the weight they were when they were sexually abused, which may interfere with weight loss attempts.^8,15 If the theory that obesity is used as an adaptive strategy by SA survivors is correct, obese women with SA histories may be less motivated to lose weight, which could contribute to reduced or unsuccessful weight loss attempts.⁸

A number of researchers have found that lesbians have higher rates of obesity than heterosexual women.^16–18 Furthermore, lesbians have reported higher rates of CSA^19,20 and ASA¹⁹ than heterosexual women. In a community sample of lesbians, Aaron and Hughes⁹ found that CSA was significantly associated with body weight. After adjusting for age, race/ethnicity, and education, women who experienced CSA were more likely to be obese (body mass index [BMI] 30.0–39.9) or severely obese (BMI ≥40) than women who did not report a history of CSA. Although this study did not include a heterosexual comparison group, it is the only published study identified that examined the association of CSA and obesity among lesbians.

Compared with heterosexuals, significantly more lesbians were in a committed relationship (74.1% vs. 66.8%, p=0.012), and had a previous mental health diagnosis (51.7% vs. 38.6%, p=0.0001). Also lesbians had completed significantly more years of education than heterosexuals (p=0.022). Although heterosexuals had a higher rate of being overweight (32.4% vs. 26.7%), lesbians had a significantly higher rate of obesity (40.2% and 30.4%, p=0.003). Lesbians also reported higher rates of SA compared with heterosexual women: lifetime SA (58.8% vs. 39.7%, p<0.0001), intrafamilial CSA (29.6% vs. 16.2%, p<0.0001), extrafamilial CSA (30.7% vs. 14.3%, p<0.0001), and ASA (40.1% and 27.3%, p=0.0001).

We found that a lesbian sexual orientation was independently related to adulthood obesity after accounting for significant covariates. These results are consistent with the literature concluding that lesbians have higher rates of obesity than heterosexual women.^16–18,21 All SA measures were associated with obesity in unadjusted analyses. When obesity was adjusted for sexual orientation and each SA variable separately, lifetime SA (p=0.037), intrafamilial CSA (p=0.0001) and extrafamilial CSA (p=0.029) were significantly related to obesity. In multivariate analysis that included other relevant demographics and previous mental health diagnosis, intrafamilial CSA was the only SA item independently associated with obesity (p=0.014). Other published reports suggest that there is an association between CSA and obesity among women; however, these prior studies did not distinguish between intrafamilial and extrafamilial CSA.^8–11,22 Our findings stress that the relationship of the perpetrator to the CSA victim could help explain the association between CSA and adulthood obesity. The nonsignificant association between ASA and obesity may explain the lack of published literature on this topic. Further investigation is needed to understand the relationship between ASA and obesity.

Other results were consistent with those of previous studies, in that race,^1,3,6,23 socioeconomic status (years of education and household income),^23,24 and mental health history²² were independently associated with obesity. Our analysis found that women who reported a household income of at least $75,000 or had a graduate degree were less likely to be obese. African American women and women who reported a history of a mental health diagnosis were more likely to be obese than Caucasian women or women who were never given a mental health diagnosis. We did not find an association between relationship status and obesity. Other studies have produced mixed results on the association between obesity and relationship/marital status.^25,26 Although age is a known risk factor for obesity,²³ we did not find an association, which may be explained by the restricted age range of our sample (35–65 years).

Comparing the relationship of SA history, lesbian sexual orientation, and adulthood obesity across studies is complex, largely because of varying definitions of SA and lesbian sexual orientation. Our findings related to SA are based on responses to two questions that asked about self-perceived SA by family and nonfamily members during childhood and one question about unwanted sexual experiences at age 18 or later. Interpretation of experiences during childhood and adulthood likely varied among participants. On the one hand, the relatively broad definition of SA used in the study may have led to inflated estimates of SA. On the other, it is possible that SA (especially CSA) may have been underreported because some women may not define their experience as abuse. Future research using more stringent definitions of SA, including more comprehensive indicators of severity (e.g., age of onset, duration of abuse), is needed. Despite the use of these broad questions to measure SA, it can be argued that if a woman reported SA in her lifetime, no matter the severity or duration of SA, her reported SA events may have some impact on her mental and physical health. Another bias, common across SA studies, is that not all women who have experienced SA may have felt comfortable reporting abuse, which means the prevalence of SA may actually be higher in this sample and the true relation of SA to obesity among women may be underestimated. Further research is needed to determine if exposure to nonsexual abuse in childhood (physical and verbal abuse, physical and emotional neglect) is also associated with obesity in adulthood.

The mental health assessment also had limitations. Those who reported having a mental health diagnosis (history of being diagnosed with depression or anxiety) represent individuals who have access to and use the healthcare system. The mental health assessment may have underestimated the rate of those with a history of a mental health diagnosis because individuals could have attained medication for depressive or anxious symptoms from their primary care physicians and may not consider themselves to be diagnosed with anxiety or depression. Furthermore, because not all people who have depression or anxiety are diagnosed, our results may underestimate the association between having a mental health diagnosis of depression or anxiety and obesity.