Sex Differences in Weight Loss among Veterans with Serious Mental Illness: Observational Study of a National Weight Management Program

PurposeObesity disproportionately burdens individuals with serious mental illness (SMI), especially women. This observational study investigated whether there were sex differences in weight loss and program participation among veterans with SMI enrolled in the Veterans Health Administration's (VHA) MOVE! weight management program.ProceduresParticipants were identified from a national cohort of 148,254 veterans enrolled in MOVE! during fiscal years 2008 through 2012 who attended two or more sessions within 12 months of enrollment. The cohort included those with International Classification of Disease, 9th Edition, Clinical Modification (ICD-9-CM) diagnoses for SMI, age less than 70 years, and weight data at baseline and one or more follow-up timepoints within approximately 1 year of enrollment (n = 8,943 men; n = 2,245 women). Linear mixed models assessed associations of sex with 6- and 12-month weight change from baseline, adjusting for demographic- and site-level variables.FindingsBoth sexes averaged 6.4 (standard deviation, 4.6) sessions within 12 months; however, women with and without SMI participated at rates double their respective proportion rates among all VHA users. Participants averaged statistically significant weight loss at 6 months (men, −2.5 lb [95% CI, −2.8 to −2.1]; women, −2.4 lb [95% CI, −3.1 to −1.7]) and 12 months (men, −2.5 lb [95% CI, −2.8 to −2.2]; women, −2.9 lb [95% CI, −3.6 to −2.2]), but no sex-based difference in absolute weight loss at either timepoint. Slightly more women achieved 5% or greater (clinically significant) weight loss at the 12-month follow-up than did men (25.7% vs. 23.0%; p < .05).ConclusionsWomen with SMI participated in MOVE! at rates equivalent to or greater than men with SMI, with comparable weight loss. More women were Black, single, had bipolar and posttraumatic stress disorder, and higher service-connected disability, suggesting areas for program customization.