Sexual orientation identity in relation to unhealthy body mass index: individual participant data meta-analysis of 93 429 individuals from 12 UK health surveys

Background: Lesbian, gay and bisexual adults are more likely than heterosexual adults to experience worse health outcomes. Despite increasing public health interest in the importance of maintaining a healthy body weight, no study has considered sexual orientation identity (SOI) and unhealthy BMI categories among adults in the UK population.

Methods: Individual participant data meta-analysis using pooled data from population health surveys reporting on 93 429 adults with data on SOI, BMI and study covariates.

Results: Adjusting for covariates and allowing for between-study variation, women identifying as lesbian (OR = 1.41, 95% CI: 1.16, 1.72) or bisexual (OR = 1.24, 95% CI: 1.03, 1.48) were at increased risk of overweight/obesity compared to heterosexual women, but men identifying as gay were at decreased risk (OR = 0.72, 95% CI: 0.61, 0.85) compared to heterosexual men. Increased risk of being underweight was seen for women identifying as 'other' (OR = 1.95, 95% CI: 1.07, 3.56), and men identifying as gay (OR = 3.12, 95% CI: 1.83, 5.38), bisexual (OR = 2.30, 95% CI: 1.17, 4.52), 'other' (OR = 3.95, 95% CI: 1.85, 8.42).

Conclusions: The emerging picture of health disparities in this population, along with well documented discrimination, indicate that sexual orientation should be considered as a social determinant of health.