Body mass index and weight change in relation to depressive and anxiety symptoms

Background Evidence on the relationship between body weight status and mental health is inconsistent. We aimed to examine the associations of body mass index (BMI) and weight change with depressive and anxiety symptoms. Methods This study was conducted among 11 402 schoolteachers. BMI was categorized as underweight (< 18.5 kg/m 2 ), normal weight (18.5 ~ < 24.0 kg/m 2 ), and overweight and obesity (≥ 24.0 kg/m 2 ). Weight change within the previous year was classified as weight loss, stable weight, weight gain, and weight fluctuation. Depressive symptoms were defined as a 10-item Center for Epidemiologic Studies Depression Scale (CESD-10) score ≥ 12. Anxiety symptoms were defined as the 7-item Generalized Anxiety Disorder scale (GAD-7) score ≥ 10. Binary logistic regression models were used to examine the corresponding cross-sectional associations. Results A total of 2 712 (23.8%) participants had depressive symptoms, and 1 028 (9.0%) had anxiety symptoms. No significant associations were observed between BMI categories and depressive and anxiety symptoms. Compared with stable weight, weight change (including weight loss, weight gain, and weight fluctuation) was associated with higher odds of depressive symptoms. The corresponding odds ratios (ORs) and 95% confidence intervals (CIs) were 1.36 (1.20, 1.54), 1.34 (1.19, 1.50), and 1.33 (1.13, 1.56), respectively. Similar associations were observed for anxiety symptoms (OR = 1.73, 95% CI: 1.45, 2.07 for weight loss; OR = 1.52, 95% CI: 1.28, 1.80 for weight gain; OR = 1.84, 95% CI: 1.47, 2.29 for weight fluctuation). Conclusions These findings suggest the potential detrimental associations of weight change with mental health among schoolteachers.