Effect of Group Counseling based on Theory of Planned Behavior on Health Promotion Lifestyle in Mothers with Overweight and Obesity during Postpartum Period: A Randomized Controlled Trial

Background: Overweight and obesity are significant risk factors for chronic diseases, with theirprevalence being a major concern during pregnancy and postpartum. This study aimed to determinethe effect of group counseling based on the Theory of Planned Behavior (TPB) on health promotionlifestyle in mothers with overweight and obesity during the postpartum period.Methods: In a randomized controlled trial conducted from July 2021 to March 2022 in Urmia,Iran, 104 mothers with overweight or obesity were randomly assigned to either an intervention or aroutine care group. Data were collected using demographic and Health-Promoting Lifestyle Profile II(HPLP-II) questionnaires. The intervention group received six weeks of TPB-based group counselingvia WhatsApp. HPLP, as the primary outcome, was measured at three distinct time points includingprior before the intervention, and one month and three months after the completion of the intervention.Data were analyzed using SPSS software version 20.0 through repeated measures analysis of variance,Chi-square, and independent t-tests. A p-value of P<0.05 was considered statistically significant.Results: The mean age of the participants was 27.06±5.98 years. In the intervention group, significantimprovements were observed from baseline to onemonth followup in total and the mean scores ofHPLP of the subscales (P<0.001), except for nutrition and spiritual growth (P>0.05). These gains weresustained three months after intervention (P<0.05). Nutrition showed a delayed effect, with a meanscore improvement from the baseline to three months after the intervention (P=0.005) and from onemonth to three months after the intervention (P=0.008). Spiritual growth also showed a delayed butsignificant improvement from one month to three months postintervention (P<0.001), but no significantchanges were observed from baseline to one month or baseline to three months (P>0.05).Conclusion: The WhatsAppbased TPB intervention effectively improved healthpromoting behavior. Itsupports the feasibility of using theorydriven digital platforms in women with overweight and obesityduring the postpartum period.The trial registration number: IRCT20210811052148N1