Background: Obesity incidence among adolescents in Australia has increased by 57% in last 3 years. Text messages are a primary communication form for adolescents and is an innovative way of delivering weight management interventions.
Aim: To determine the effectiveness of text message interventions on body mass index (BMI) in adolescents and describe characteristics that are common to effective interventions.
Methods: Systematic review with meta-analysis including: (i) randomised controlled trials of text message lifestyle interventions; (ii) participants are adolescents 10-19 years; and (iii) outcomes focussed on obesity prevention or management. Primary outcome was objective or self-report change in BMI.
Results: In total 4362 records were identified, and 211 full-text articles were assessed for eligibility. To date, 7 unique studies have been identified including 720 participants with an average age 14.2±0.9 years, BMI 29.7±1.6 kg/m-2 and 50% female (31-100%). Five studies were conducted in USA, and 1 each in Australia, China and Iran. Active intervention duration was 2-12-months, with a median of 1 text message/week. BMI (n=4) and BMI z-sore (n=3) decreased on average in intervention participants by 1.2±1.8 kg/m2 and 0.1±0.1 units compared to controls at 6-months, respectively. Three studies included both active and extended intervention phases, with 2 studies utilising text messages only during extended phase. Four studies used one-way text message communication and 3 used two-way. Five studies used semi or personalised text messages, which provided specific behaviour change techniques, such as prompting practice, to encourage achievement of personal behavioural goals.
Conclusions: Preliminary results indicate that low-dose text message interventions may be an effective weight management tool for adolescents with overweight. However, there is limited evidence for higher dose text messages interventions and interventions targeting adolescents who are at risk of obesity (BMI on 85th-95th percentile). This research highlights the potential of scalable interventions targeting weight management in adolescents.