Prevalence of Clinical Obesity Based on Updated Definitions Among Women by Sexual Identity: Results from 2001 to 2016 National Health and Nutrition Examination Survey

Abstract

Introduction:

Previous work has consistently shown a higher prevalence of obesity based on body mass index (BMI) among lesbian women and, more recently, also among bisexual women. New recommendations on defining clinical obesity suggest the inclusion of other physical health measures related to physiological health and/or physical limitations. Therefore, the purpose of this study is to examine sexual identity-based differences in clinical obesity among women using updated definitions.

Methods:

2001–2016 National Health and Nutrition Examination Survey data were analyzed in 2024 to 2025. Body mass index, metabolic biomarkers, and physical functioning were used to estimate prevalence of clinical obesity for each sexual identity group (heterosexual n = 11,054; lesbian/gay n = 171; bisexual n = 464; something else n = 94; “not sure” n = 289). Logistic regression models were fit to assess sexual identity-based differences in clinical obesity. Covariates included age, race/ethnicity, income, education, and relationship status.

Results:

With metabolic biomarkers, there was no statistically significant difference in prevalence of clinical obesity between lesbian/gay and heterosexual women. With physical functioning only, prevalence was higher among lesbian/gay than heterosexual women (OR range: 2.0–2.5). Bisexual women consistently had higher prevalence of clinical obesity than heterosexual women (OR range: 1.2–2.1) across all definitions. There were no other sexual identity-based differences in clinical obesity.

Conclusion:

Based on updated recommendations, physical functioning may better capture clinical obesity among lesbian/gay and bisexual than heterosexual women with BMI ≥30 kg/m² than metabolic biomarkers. However, bisexual women continued to have higher risk for clinical obesity, and additional work is needed to better understand the factors that contribute to this disparity.