The Effect of a Behavioral Weight Loss Intervention With or Without Exercise on Depressive Symptoms

Abstract

Depressive symptoms have been associated with less weight loss in some behavioral weight loss interventions (BWLI), and although it has been speculated that adding moderate-to-vigorous physical activity (MVPA) may improve outcomes, the relationship is not well understood. PURPOSE: To examine the relationship between weight loss, MVPA participation, and depressive symptoms over time in subjects enrolled in a BWLI. METHODS: Secondary analyses of depressive symptoms and weight loss in sedentary subjects (n=379; 45.0±7.9 years; BMI=32.4kg/m2±3.8) enrolled in a BWLI and randomized to a reduced calorie diet (DIET, N=104), diet plus a moderate dose of MVPA (MOD-EX, N=97), or diet plus a high dose of MVPA (HIGH-EX, N=102) were completed. All groups reduced energy intake (1200-1800 kcal/day), received weekly intervention sessions (months 1-6), followed by 2 group and 2 telephone contacts per month (months 7-12). MOD-EX was prescribed unsupervised MVPA that progressed to 150 min/wk, and HIGH-EX was progressed to 250 min/wk. Depressive symptoms (CES-D) and weight were assessed at 0, 6, and 12 months. RESULTS: Weight decreased [6mo:-9.18±5.9kg; 12mo:-10.0±7.8 kg] and depressive symptoms modestly increased from baseline to 6 months [BL: 6.45± 2.34; 6mo: 7.05](p<0.001) and baseline to 12 months [BL: 6.45± 2.34; 12mo: 6.93](p<0.05), with no significant differences between randomized groups. There was a modest, yet significant correlation between baseline CES-D score and weight change at months 6 (r=.126) and 12 months (r=.122)(p<0.05). Subjects who completed 6 months of the intervention (n=337) had significantly lower baseline CES-D scores compared to the non-completers (n=42) (p<.05), but there were no differences for 12 month completers (p=.49). CONCLUSIONS: The data revealed an inverse relationship between baseline depressive symptoms and success in the BWLI. This relationship was not different between DIET, MOD-EX, and HIGH-EX, indicating that exercise participation may not influence this relationship. While depressive symptoms increased slightly over time regardless of group assignment, the 6 month completers had lower baseline depressive symptoms than non-completers. Thus, baseline depressive symptoms may be an important marker of both success and attrition in a BWLI.