A fully remote, app-based dietary intervention – known as Goals for Reaching Optimal Wellness (GROWell) – did not significantly reduce excessive gestational weight gain (GWG) or postpartum weight retention (PPWR) compared with an educational control, according to a randomized controlled trial published in BMC Pregnancy and Childbirth.
The trial enrolled 453 pregnant women in California with pre-pregnancy body mass index (BMI) between 25 and 42 kg/m², recruited between January 2021 and March 2023. Participants were 10–16 weeks’ gestation with uncomplicated singleton pregnancies. Using a double-blind randomized design, 216 women were assigned to the GROWell intervention and 237 to an attention control group.
GROWell delivered personalized dietary goals through a mobile app or text messaging platform. Drawing on self-regulation and social cognitive theory, participants received two tailored dietary goals at a time – one focused on increasing nutrient-dense foods and one on reducing less healthy options. Messaging was individualized based on dietary habits, readiness to change, and preferences, and reinforced with weekday prompts, weekly adherence check-ins, and remote weight monitoring using a study-provided Bluetooth scale.
The control group received similarly structured, personalized messages on pregnancy, infant development, and postpartum topics, but without nutrition or diet guidance. Both groups also had access to the Bluetooth scale for self-weighing.
Primary outcomes were excessive GWG – defined according to Institute of Medicine recommendations – and PPWR at 6 months postpartum. Modified Poisson regression models were used to estimate risk ratios.
Excessive GWG occurred in 35% of women in the intervention group and 36% in the control group. At 6 months postpartum, 23% of women in the intervention arm and 26% in the control arm met criteria for PPWR. After adjustment for demographic and behavioral covariates, the intervention was not associated with significant reductions in either outcome.
Although the intervention did not outperform the control condition, overall rates of excessive GWG and PPWR in both groups were lower than commonly reported national and international averages, where more than half of women with overweight or obesity exceed recommended pregnancy weight gain. The study authors suggest several potential explanations for these rates, including relatively high participant education levels, self-selection of motivated individuals, and the effect of having access to the Bluetooth scale and being able to regularly self-weigh.
The study’s strengths include its racially and ethnically diverse cohort, decentralized social media-based recruitment, and fully remote design, which broadened access beyond traditional academic medical centers. Adherence to weekly dietary goal tracking averaged 72% among intervention participants over the course of the study.
The investigators conclude that future studies should explore how GROWell impacts participants when it is delivered prior to conception, as well as incorporating physical activity components, culturally tailoring content and goals to specific demographics, and improving the program’s reach to include participants with lower educational levels.
Source: BMC Pregnancy and Childbirth.