The relation between body mass index and self-rated mental health among older adults: do racial/ethnic differences exist?

ABSTRACT

OBJECTIVES: To examine racial and ethnic differences in the relation between body mass index (BMI) and self-rated mental health (SRMH) among community-dwelling older adults. DESIGN: Cross-sectional analyses of nationally representative data from the Collaborative Psychiatric Epidemiology Surveys. SETTING: In-person household interviews. PARTICIPANTS: Older adults aged 60 and older (N = 2,017), including non-Hispanic white (N = 547), black (N = 814), Hispanic (N = 401), and Asian (N = 255) patients. MEASUREMENTS SRMH was measured with a single item, "How would you rate your own mental health?" BMI categories were underweight (<18.5 kg/m(2)), healthy weight (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), and obese (≥30.0 kg/m(2)). RESULTS: A two-way analysis of covariance showed that after controlling for covariates, there was a significant main effect of race/ethnicity on SRMH, but the main effect of BMI was not significant. A significant interaction between BMI and race/ethnicity on SRMH was also found. The linear contrasts showed that white adults had a significant trend showing that SRMH decreased with increases in BMI, whereas black adults had a significant trend showing that SRMH increased with increases in BMI. The linear trends for Hispanic and Asian adults were not significant. CONCLUSIONS: There were significant racial/ethnic differences in the relation between BMI and SRMH. Understanding the role of race/ethnicity as a moderator of the relation between BMI and mental health may help improve treatment for older adults with unhealthy weights. Clinical implications are also discussed.