Nutrition, Behavior Change and Physical Activity Outcomes From the PEARS RCT-An MHealth-Supported, Lifestyle Intervention Among Pregnant Women With Overweight and Obesity

Diet quality and physical activity positively impact pregnancy outcomes among women with obesity, but successful lifestyle interventions require intense clinician time. We aimed to investigate the impact of a behavioral-lifestyle intervention (PEARS) supported by a smartphone app among pregnant women with overweight and obesity, on nutrient intake, behavioral stage-of-change and physical activity. Pregnant women (BMI 25-39.9 kg/m, measured, = 565) were randomized at 15.6 weeks' gestation to the intervention ( = 278), or a control group ( = 287) (ISRCTN29316280). The intervention was grounded in behavior-change theory. Participants received nutrition (low glycaemic index and healthy eating) and exercise advice, a smartphone app and fortnightly emails. The control group received usual care which does not include dietary advice. At baseline and 28 weeks' gestation, dietary data were obtained through 3-day food diaries ( = 290 matched), and stage-of-change and physical activity data were self-reported. App usage data were collected. There were no differences between the groups at baseline. Compared with the control group, the intervention group had improved dietary intakes post-intervention with; lower glycaemic index (MD -1.75); free sugars (%TE) (MD -0.98); fat (%TE) (MD -1.80); and sodium (mg) (MD -183.49). Physical activity (MET-minutes/week) was higher in the intervention group post-intervention (MD 141.4; 95% CI 62.9, 219.9). The proportion of participants at "maintenance" stage-of-change for physical activity was higher in the intervention group (56.3 vs. 31.2%). App use was associated with lower glycaemic index and less energy from free sugars, but not with physical activity. A behavioral-lifestyle intervention in pregnancy supported by a smartphone app improved dietary intakes, physical activity, and motivation to engage in exercise.