# Family Fit: Promoting Family-Based Physical Activity and Weight Gain Prevention Through Mobile Technology > **NIH NIH R21** · UNIVERSITY OF FLORIDA · 2022 · $190,625 ## Abstract PROJECT SUMMARY/ABSTRACT Epidemic rates of overweight and obesity in US children put millions at risk for chronic disease (e.g., Type 2 diabetes, some cancers). Given that excessive childhood weight gain is often gradual, obesity prevention efforts should also include normal weight children. Regular physical activity (PA) contributes to healthy weight maintenance though the weight regulation benefits of PA are only derived when activity reaches moderate- to vigorous-intensity PA (MVPA) (not light-intensity PA). However, recommended levels of MVPA are only reached by less than 5% of adults and only 42% of children (per objective measures), and MVPA tends to further decline during adolescence. Interventions are needed before this period (i.e., ages 9-12 years), to prevent declines and capitalize on this ideal period for family-based interventions, given the influence parents still hold as role models. Interventions that reach families could prevent declines in PA and simultaneously help children and adults be more active, but effective interventions with potential for widespread dissemination are lacking. Thus, we propose to refine and test a mobile app-delivered family-based PA intervention that addresses current gaps in family-based interventions and technology tools, by directly targeting MVPA with a novel PA target, integrating with a wearable PA device (Fitbit), offering skills training in positive family communication, linking to a parent social network, and providing opportunities for family support progress displays and theory-based messaging. We will conduct app usability testing and a pilot randomized trial with insufficiently physically active parent-child dyads (child 9-12 years old) to compare the Family Fit intervention to a Fitbit Only condition. The objective of the proposed study is to refine our app-based intervention and gather preliminary data on the feasibility and acceptability of the approach to finalize the design of the subsequent larger efficacy trial. Aim 1: Refine the Family Fit App. We will translate our intervention into an app. Leveraging a user-centered approach, we will iteratively refine the app with the feedback of an advisory board of n=12 parent-child dyads (child 9-12 years old). Aim 2: Pilot Feasibility Trial. We will randomize 60 parent-child dyads to the Family Fit Condition (intervention) or the Fitbit Only Condition (comparison) where dyads will receive only Fitbits. The primary outcome will be the feasibility of the Family Fit intervention after 12 weeks and sustainability after an additional 6 weeks. Feasibility outcomes are recruitment, app use rates, acceptability, and retention. We will also explore changes in dyad MVPA, Family Systems Theory processes (e.g., family cohesion, communication, support), and BMI (BMI for adults, BMI percentile for children) at 12 and 18 weeks. ## Key facts - **NIH application ID:** 10459232 - **Project number:** 5R21HD100743-02 - **Recipient organization:** UNIVERSITY OF FLORIDA - **Principal Investigator:** Danielle Erin Jake-Schoffman - **Activity code:** R21 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2022 - **Award amount:** $190,625 - **Award type:** 5 - **Project period:** 2021-08-01 → 2025-07-31 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/10459232 ## Citation > US National Institutes of Health, RePORTER application 10459232, Family Fit: Promoting Family-Based Physical Activity and Weight Gain Prevention Through Mobile Technology (5R21HD100743-02). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10459232. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*