The skinny on sexual risk: the effects of BMI on STI incidence and risk.

Few studies examine the influence of body mass index (BMI) on sexual risk. The purpose of this study was to determine whether BMI among 704 young mothers (ages 14-25) related to STI incidence and sexual risk. We examined the effect of BMI groups (normal weight, overweight, and obese) at 6 months postpartum on STI incidence and risky sex (e.g., unprotected sex, multiple partners, risky and casual partner) at 12 months postpartum. At 6 months postpartum, 31% of participants were overweight and 40% were obese. Overweight women were more likely to have an STI (OR = 1.79, 95% CI = 1.11-2.89, P < .05) and a risky partner (OR = 1.64, 95% CI = 1.01-2.08, P < .05) at 12 months postpartum compared to normal weight women. However, obese women were less likely to have an STI than normal weight women (OR = .57, 95% CI = .34-.96, P < .01). BMI related to STI incidence and sexual risk behavior. Integrated approaches to weight loss and sexual risk prevention should be explored.