Importance Weight gain occurs commonly in young adults and has adverse effects on health.
Objective To compare 2 self-regulation interventions vs control in reducing weight gain in young adults over a mean follow-up of 3 years.
Design, Setting, and Participants Randomized clinical trial in 2 academic settings of 599 participants aged 18 to 35 years with body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) of 21.0 to 30.0, recruited via mailings and emails from August 2010 to February 2012. Data were analyzed from January 2015 to January 2016.
Interventions Participants were randomized to control, self-regulation plus small changes, or self-regulation plus large changes. Both interventions focused on frequent self-weighing to cue behavior changes. “Small changes” taught participants to reduce intake and increase activity, both by approximately 100 calories per day. “Large changes” focused on losing 2.3 to 4.5 kg initially to buffer against expected weight gain.