Introduction: Short message service [SMS] text messaging and e-mail are emerging as cost-effective methods for improving weight management, however optimal frequency and timing are yet to be determined. This study combined a 3-month face-to-face cognitive-behavioural therapy (CBT) group program with technological support of varying types and intensity to examine changes in anthropometric, psychological and behavioural variables.
Method: Sixty obese adults were randomised to CBT plus intensive technological support (two-way SMS and e-mail communication from 0-9 months) or CBT plus minimal technological support (one-way SMS support from 0-6 months). Assessments at baseline, 3-, 6-, 9-, and 15-months measured a range of outcomes including weight, BMI, waist circumference, binge-eating tendencies, weight self-efficacy, and weight-control cognitions and behaviours.
Findings: Intention-to-treat analyses revealed participants in both conditions lost 4.9% of baseline weight by the end of the 3-month face-to-face program, continued to lose weight at 6-months (7.1%) and 9-months (8.8%), and maintained post-treatment gains at 15-months (7.9%). Results are comparable to traditional behavioural weight loss programs involving weekly face-to-face treatment for 24-weeks, which produce weight losses of 8-10%. Participants demonstrated significant reductions in binge-eating and frequency of problematic weight-control cognitions and behaviours, and increased confidence to abstain from non-hungry eating. No significant differences were observed between groups on any of the outcome variables.
Conclusion: Technological support combined with CBT produced weight loss maintenance following face-to-face treatment. It was found that SMS support, which was the most cost effective and least intensive intervention (i.e., in terms of therapist time), was as effective as the more costly and intensive e-mail support, suggesting that daily SMS support is a cost-efficient way of enhancing weight outcomes.