Background
Few weight-loss interventions are evaluated for longer than a year, and even fewer employ social and mobile technologies commonly used among young adults. We assessed the efficacy of a two-year, theory-based weight-loss intervention that was remotely and adaptively delivered via integrated user-experiences with 1) Facebook, 2) mobile apps, 3) text messaging, 4) emails, 5) a website, and 6) technology-mediated communication with a health coach.
Methods
From May 2011 to May 2012, 404 overweight or obese college students (aged 18 to 35 years) from three universities in San Diego, CA were randomized using a computer-based procedure to receive either the intervention (n=202) or general information about health and wellness (control group, n=202). The primary outcome was objectively measured weight in kg at 24 months, and differences between groups were evaluated using linear mixed-effects regression and an intention-to-treat framework. The trial was registered with ClinicalTrials.gov NCT01200459.
Findings
Participants’ mean (standard deviation (SD)) age was 22·7 (3.8) years. They were 70% female and 31% Hispanic. Mean (SD) body mass index was 29·0 (2.8) kg/m2. At 24 months, weight was assessed in 341 (84%) participants, but all 404 were included in analyses. Weight, adjusted for sex, ethnicity, and college, was significantly less in the intervention group compared to the control group at 6 months (−1·33 kg, 95% confidence interval (CI) = −2·36 to −0·30, p = 0·011) and 12 months (−1·33 kg, 95% CI =−2·30 to −0·35, p = 0·008). However, differences between groups at 18 months (−0·67 kg, 95% CI = −1·69 to 0·35, p = 0·200) and 24 months (−0·79 kg, 95% CI = −2·02 to 0·43, p = 0·204) were not significant.
Interpretation
Social and mobile technologies may facilitate limited short-term weight loss among young adults, but as utilized in this intervention, these approaches did not produce sustained reductions in weight.
