Weight loss methods and risk of depression: Evidence from the NHANES 2005-2018 cohort

Weight loss behaviors are increasingly common worldwide. While healthy weight loss methods, such as calorie control and exercise, can improve both physical and mental health, harmful practices-such as extreme dieting and the misuse of diet pills-may contribute to depressive symptoms. Understanding the psychological impact of different weight loss strategies is essential for promoting overall well-being.

Data from 9334 non-pregnant participants aged 20-79 years from the 2005-2018 National Health and Nutrition Examination Survey (NHANES) were analyzed. The sample consisted of 60.72 % women and 39.28 % men, with a median age of 47 years and a median BMI of 28.84. Depressive symptoms were assessed using the PHQ-9 scale. Weight loss methods were categorized into healthy practices (e.g., calorie control, exercise) and harmful practices (e.g., extreme dieting, diet pills). Logistic regression models were applied, adjusting for demographic and health factors.

Protective methods, including switching to lower-calorie foods (OR = 0.80, 95 % CI = 0.68-0.94), exercising (OR = 0.61, 95 % CI = 0.53-0.72), and eating more fruits and vegetables (OR = 0.78, 95 % CI = 0.66-0.92), were associated with a reduction in depressive symptoms. In contrast, harmful methods such as skipping meals (OR = 1.71, 95 % CI = 1.45-2.02), using diet pills (OR = 1.90, 95 % CI = 1.34-2.69), and vomiting (OR = 2.61, 95 % CI = 1.62-4.21) increased the risk of depressive symptoms. The number of harmful methods was positively correlated with increased depressive symptom risk (OR = 2.72, 95 % CI = 2.09-3.54), while a higher number of protective methods was linked to a decreased risk (OR = 0.50, 95 % CI = 0.37-0.68).

The emotional impact of weight loss practices is significant. Healthy weight loss strategies, such as exercise and calorie control, reduce the risk of depressive symptoms, whereas harmful methods increase the risk. These findings underscore the importance of promoting safe and sustainable weight loss methods to protect both physical and mental health.