BACKGROUND: Using regulatory focus theory, an intervention of daily weight 
loss-sustaining messages was developed and tested for acceptability, 
feasibility, and efficacy on helping people sustain weight loss.
METHODS: Participants (n = 120) were randomized to a promotion, prevention, or 
an attention-control text message group after completion of a weight loss 
program. Participants completed baseline assessments, and reported their weight 
at 1 and 3 months postbaseline.
RESULTS: Participants found the message content and intervention acceptable and 
valuable. A minimum of one message per day delivered at approximately 8:00 am 
was deemed the optimal delivery time and frequency. The sustained weight loss 
rate at month 3 for the control, promotion, and prevention groups was 90%, 95%, 
and 100%, respectively. Medium-to-large effects were observed for the promotion 
and prevention groups at month 1 and for prevention at month 3 relative to 
controls. The mean weight loss for promotion and prevention was 15 pounds, 
compared with 10 in the controls at month 3.
CONCLUSION: A clinically significant decrease in mean weight, higher rate of 
sustained weight loss, and medium-to-large effects on sustained weight loss 
occurred in the promotion and prevention interventions. Tools such as this text 
message-based intervention that are constructed and guided by evidence-based 
content and theoretical constructs show promise in helping people sustain 
healthy behaviors that can lead to improved health outcomes.