Feasibility and efficacy of a novel technology-based approach to harness social networks for weight loss: the NETworks pilot randomized controlled trial.

OBJECTIVE: Harnessing social support from existing social ties represents a key weight control practice. This trial evaluated an intervention that provided health-promoting technologies for leveraging the influence of existing social ties. METHODS: Volunteers (N = 36) with a body mass index between 25 and 55 kg m-2 were randomized to a 16-week, in-person, technology-supported behavioural weight-loss treatment (standard behavioural treatment) or the same programme supplemented by providing self-selected members of participants' social networks with a digital body-weight scale and Fitbit Zip physical activity tracker (ENHANCED). RESULTS: Average weight losses from baseline to 16 weeks did not significantly differ between groups (standard behavioural treatment, 5.30%, SD =3.93%; ENHANCED, 5.96%, SD = 5.19%, p = 0.63). By the 1-year follow-up, standard behavioural treatment had lost 5.63%, SD = 8.14% of baseline weight versus 4.73%, SD = 9.43% for ENHANCED (p = 0.82). ENHANCED reported self-weighing on more days than did standard behavioural treatment (p = 0.03). Most participants reported high programme satisfaction. Similar improvements were observed in perceived social support for diet and exercise from baseline to 16 weeks in both groups (ps < 0.05) but regressed by 1 year (ps < 0.01). CONCLUSION: Although feasible to implement, this technology-based, social support approach failed to enhance outcomes of a face-to-face, group-based behavioural weight-loss treatment.