Impact of an Internet-Based Lifestyle Intervention on Behavioral and Psychosocial Factors During Postpartum Weight Loss.

ABSTRACT

OBJECTIVE: This cluster randomized trial tested whether an effective internet-based weight-loss intervention for low-income, postpartum women resulted in greater improvements in targeted social cognitive theory (SCT) constructs and psychosocial outcomes. METHODS: Fit Moms/Mamás Activas was a 12-month cluster randomized controlled trial of 370 postpartum women at 12 Special Supplemental Nutrition Program for Women, Infants, Children (WIC) clinics that were randomly assigned to intervention or standard WIC. SCT constructs (weight-control behaviors, cognitive restraint, disinhibition, self-efficacy, social support, body image) and psychosocial outcomes (depressive symptoms and stress) were measured at study entry and after 6 and 12 months. RESULTS: The intervention versus standard WIC resulted in greater 12-month increases in weight-control behaviors (3.28 points [95% CI 1.06-5.50]), self-monitoring of weight and eating (2.28 points [1.17-3.40]), and cognitive restraint (1.93 points [0.78-3.08]) (all P ≤ 0.004). The intervention effect was only modestly (ηp 2 = 0.02) mediated by improvements in these factors. No significant group by time effect was observed for disinhibition, self-efficacy, social support, body image, depressive symptoms, or stress. CONCLUSIONS: Among low-income postpartum women, an effective internet-based weight-loss program resulted in improved weight-control behaviors and cognitive restraint but did not affect other SCT targets and psychosocial outcomes.