Behavioral Predictors of Weight Regain in Postmenopausal Women: Exploratory Results From the Breast Cancer and Exercise Trial in Alberta

Abstract

Objective: This secondary analysis assessed associations between changes in energy balance and sleep behaviors and the risk of weight regain following exercise-induced weight loss. Methods: Of 400 participants initially randomized in the Breast Cancer and Exercise Trial in Alberta (BETA), 227 lost weight following the moderate- to vigorous-intensity exercise intervention (−4.2 ± 3.6 kg) and were included in this analysis. Self-reported energy intake (EI), sleep duration, quality and timing, and objective measurements of physical activity (PA) and sedentary time were collected at the end of the intervention and the end of follow-up. Linear regression models assessed associations between changes in these behaviors and risk of weight regain during follow-up. Results: Participants regained 43% of the weight lost during follow-up. Reductions in moderate to vigorous PA (β = −1.00; 95% CI = −1.74 to −0.25 h/d; P = 0.01) and steps per day (β = −0.0003; 95% CI = −0.0005 to −0.0001 steps/d; P = 0.004); increases in sedentary time (β = 0.54; 95% CI = 0.67 to 1.02 h/d; P = 0.03), EI (β = 0.001; 95% CI = 0.0003 to 0.002 kcal; P = 0.01), and fat intake (β = 0.004; 95% CI = 0.001 to 0.006 kcal; P = 0.002); and delayed sleep timing midpoint (β = 0.02; 95% CI = 0.004 to 0.03 min; P = 0.01) were associated with weight regain during follow-up. Conclusions: These exploratory results suggest that reductions in moderate to vigorous PA; increases in EI, fat intake, and sedentary time; and delayed sleep timing midpoint were significantly associated with risk of weight regain.