The mFIT (Motivating Families with Interactive Technology) Study: a Randomized Pilot to Promote Physical Activity and Healthy Eating Through Mobile Technology

Scalable and convenient programs for family obesity prevention have proven difficult to design/implement. Mobile technology could be helpful tools to engage busy families. The Motivating Families with Interactive Technology (mFIT) study tested the feasibility, acceptability, and effectiveness of two remotely delivered family-based programs targeting physical activity (PA) and healthy eating (HE). Parent–child dyads were randomized to one of two 12-week mobile interventions delivered via weekly email newsletters; programs differed in focus of content (individual vs. family) and method of tracking (paper vs. mobile website). At baseline and 12 weeks, height and weight were objectively measured and participants completed questionnaires. Multivariable models were used to examine changes from baseline to 12 weeks by parent/child, group, and time; Cohen’s d was used to calculate effect sizes. Of the 33 randomized dyads (parents 43 ± 5.8 years, 87.9% female, 69.7% white, BMI 31.1 ± 8.3 kg/m 2 ; children 11 ± 0.9 years, 63.6% female, 66.7% white, BMI 77.6 ± 27.8 percentile), 31 (94.0%) had follow-up data. Baseline means for all measures of parent–child communication and engagement were high. There were no group by time differences for PA or HE. However, combining groups and parents/children, there was a significant increase in average daily steps (1397 steps, p = 0.04, d = 0.4) and servings of fruit (0.3 servings, p = 0.02, d = 0.2), a marginally significant decrease in children’s daily servings of sugar-sweetened beverages (− 0.1 servings, p = 0.05, d = −0.1), and good adherence to self-monitoring protocols. The mFIT program showed excellent feasibility and acceptability as a low-cost, remotely delivered family intervention for PA and HE promotion.