A Mobile Health Lifestyle Program for Prevention of Weight Gain in Young Adults (TXT2BFiT): Nine-Month Outcomes of a Randomized Controlled Trial

Background: The unprecedented rise in obesity among young adults, who have limited interaction with health services, has not been successfully abated. Objective: The objective of this study was to assess the maintenance outcomes of a 12-week mHealth intervention on prevention of weight gain in young adults and lifestyle behaviors at 9 months from baseline. Methods: A two-arm, parallel, randomized controlled trial ( RCT) with subjects allocated to intervention or control 1: 1 was conducted in a community setting in Greater Sydney, Australia. From November 2012 to July 2014, 18-to 35-year-old overweight individuals with a body mass index ( BMI) of 25-31.99 kg/m(2) and those with a BMI = 23 kg/m(2) and a self-reported weight gain of = 2 kg in the past 12 months were recruited. A 12-week mHealth program "TXT2BFiT" was administered to the intervention arm. This included 5 coaching calls, 96 text messages, 12 emails, apps, and downloadable resources from the study website. Lifestyle behaviors addressed were intake of fruits, vegetables, sugar-sweetened beverages ( SSBs), take-out meals, and physical activity. The control group received 1 phone call to introduce them to study procedures and 4 text messages over 12 weeks. After 12 weeks, the intervention arm received 2 further coaching calls, 6 text messages, and 6 emails with continued access to the study website during 6-month follow-up. Control arm received no further contact. The primary outcome was weight change ( kg) with weight measured at baseline and at 12 weeks and self-report at baseline, 12 weeks, and 9 months. Secondary outcomes were change in physical activity ( metabolic equivalent of task, MET-mins) and categories of intake for fruits, vegetables, SSBs, and take-out meals. These were assessed via Web-based surveys. Results: Two hundred and fifty young adults enrolled in the RCT. Intervention participants weighed less at 12 weeks compared with controls ( model beta=-3.7, 95% CI -6.1 to -1.3) and after 9 months ( model beta=-4.3, 95% CI -6.9 to -1.8). No differences in physical activity were found but all diet behaviors showed that the intervention group, compared with controls at 9 months, had greater odds of meeting recommendations for fruits ( OR 3.83, 95% CI 2.10-6.99); for vegetables ( OR 2.42, 95% CI 1.32-4.44); for SSB ( OR 3.11, 95% CI 1.47-6.59); and for take-out meals ( OR 1.88, 95% CI 1.07-3.30). Conclusions: Delivery of an mHealth intervention for prevention of weight gain resulted in modest weight loss at 12 weeks with further loss at 9 months in 18- to 35-year-olds. Although there was no evidence of change in physical activity, improvements in dietary behaviors occurred, and were maintained at 9 months. Owing to its scalable potential for widespread adoption, replication trials should be conducted in diverse populations of overweight young adults.