Feasibility, Acceptability, and Preliminary Effectiveness of an Adaptive Text Messaging Intervention for Adolescent Weight Control in Primary Care

Objective: Behavioral interventions for adolescent weight control are often difficult to access because they are rarely provided in primary health care. This study was designed to assess the feasibility, acceptability, and preliminary effectiveness of a motivational interviewing plus adaptive text messaging intervention for adolescent weight control delivered in primary care. Methods: Forty-seven overweight adolescents (aged 13-18 years) participated in a single, hour-long, in-person motivational interviewing session in their primary care pediatrician's office with a clinical psychology doctoral student. All participants monitored diet, physical activity, and weight over 6 months and reported this information nightly via text message. Participants were selected randomly to receive computer-tailored adaptive text messages 3 times per day at mealtimes as an additional intervention component. Results: Participants found the intervention to be acceptable and beneficial for promoting weight-related behavior change. Adherence to self-monitoring was significantly higher in the adaptive text messaging group. Although body mass index z-score (zBMI) change was not significantly different across treatment groups, participants receiving the adaptive text message intervention demonstrated a reduction of .32 zBMI standard deviation units from before to after intervention, t(28) = −2.84, p < .01, d = .54, whereas zBMI did not change for individuals receiving the control intervention. Several domains of weight-related quality of life improved during the intervention period irrespective of treatment assignment. Conclusions: Study findings suggest that a behavioral weight control intervention delivered in a primary care is acceptable/feasible and may produce reductions in zBMI. Fully powered studies to further evaluate this intervention approach are warranted. Implications for Impact Statement This pilot trial demonstrates that adaptive text messaging is a feasible, acceptable method for delivering weight control intervention content as an addition to in-person treatment for overweight adolescents. Furthermore, our findings suggest that interventions including adaptive text messages may improve self-monitoring adherence and produce superior weight loss outcomes.