Use of Extrinsic Motivators to Improve the BMI of Obese or Overweight Adolescents: Systematic Review

Background The prevalence of overweight and obesity is increasing at an alarming rate in children and adolescents worldwide. Given the dimensions of the problem, the treatment of childhood obesity is considered extremely important. Current evidence indicates that behavioral and cognitive behavioral strategies combined with diet and physical activity approaches may assist in reducing adolescent obesity. Objective The purpose of this systematic review was to evaluate the use of extrinsic motivators for improving the BMI of obese or overweight adolescents. Methods The inclusion criteria were as follows: (1) overweight or obese adolescents, (2) intervention using extrinsic motivators, and (3) outcome variables related to weight status. The exclusion criterion was the presence of an associated chronic disease. The search process was conducted in PubMed and Web of Science (last searched on April 23, 2023). The risk of bias was evaluated independently by 2 authors using Cochrane tools (RoB2 [randomized controlled trials], ROBINS-I, and ROBINS-E). Results From 3163 studies identified, 20 articles (corresponding to 18 studies) were included in the analysis. The studies differed in terms of study design, sample size, follow-up duration, outcomes reported, and extrinsic motivators used. Most of the studies had videogames or apps as interventions. Of the 18 studies, 9 (50%) reported a statistically significant decrease in BMI. The most used extrinsic motivators were “motivation” (n=13), “feedback” (n=10), and “rewards” (n=9). Among the motivators, “reminders” (100%) and “peer-support” (80%) appeared to have high impacts on BMI reduction. Conclusions The heterogeneity of the included studies made analysis difficult. No study evaluated extrinsic motivators in isolation. Most of the studies had a moderate or high risk of bias. The extrinsic motivators “reminders” and “peer-support” appeared to be useful. Further studies are needed, and these should include well-designed randomized controlled trials and studies involving homogeneity in BMI measures, consistent extrinsic motivator definitions, and longer durations to better understand the long-term impacts of extrinsic motivators on weight management success.