PURPOSE: Overweight/obese individuals are at an increased risk for depression with some evidence of a bidirectional association. The preventative effects of physical activity among overweight/obese individuals have been well documented; however, less is known on how the duration of overweight/obesity alters the association with negative health outcomes. Therefore, the purpose of this investigation was to determine how the classification, and more specifically duration, of overweight/obesity alters the association between physical activity and depressive symptoms.
METHODS: The 2005-2006 National Health and Nutrition Examination Survey (NHANES) data were used (n = 764), and individuals were divided into six mutually exclusive groups based on physical activity status, weight classification (measured BMI), and duration of weight classification (assessed via recall). Multivariable linear and logistic regression analyses were computed to examine odds of depressive symptoms (patient health questionnaire (PHQ)-9) among groups.
RESULTS: After adjusting for covariates, only individuals who were inactive and overweight/obese at the examination and 10 years prior were at an increased odds of depressive symptoms in comparison to those who were active and normal weight (odds ratio (OR) = 2.40; 95 % confidence interval (CI) 1.03, 5.61; p = 0.04).
CONCLUSION: Physical activity appeared to ameliorate the association with depressive symptoms independent of overweight/obesity classification or duration. The cyclic nature of overweight/obesity and depression (i.e., bidirectional association) appears to increase the odds of depression as the length of overweight/obesity is increased. These results provide support for clinicians to assess not only their clients' current BMI but also the duration in which they have been at a certain weight classification and to further promote physical activity as a preventative measure against depressive symptoms.