Use of Extrinsic Motivators to Improve the Body Mass Index of Obese or Overweight Adolescents: A Systematic Review.

BACKGROUND

The prevalence of overweight and obesity is increasing at an alarming rate in children and adolescents worldwide. Given the dimension of the problem, treatments of childhood obesity are recognized as of extreme importance. Current evidence indicates that behavioural and cognitive behavioural strategies combined with diet and physical activity approaches may assist in reducing adolescent obesity.

OBJECTIVE

The purpose of this systematic review is to evaluate the use of extrinsic motivators in 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, 3) outcome variables related to weight status. The exclusion criteria were associated chronic disease. The search process was conducted in PubMed and Web of Science (last searched on 23/04/2023). The risk of bias was evaluated independently by two authors with the Cochrane's tools: RoB2 (RCT), ROBINS-I and ROBINS-E.

RESULTS

From 3,163 studies identified, 20 articles (corresponding to 18 studies) were included in the analysis. The studies differ in study design, sample size, follow-up duration, outcomes reported, and extrinsic motivators used. Most of the studies had videogames or apps as intervention. Nine studies (50%) showed a statistically significant decrease of BMI. The most used extrinsic motivators were "Motivation" (n=13), "Feedback" (n=10) and "Rewards" (n=9), and the ones that seem to have a higher impact on decreasing BMI are "Reminders" (100%) and "Peer-support" (80%).

CONCLUSIONS

The heterogeneity of studies makes analysis difficult. No study has evaluated the extrinsic motivators in isolation. Most of the studies have a moderate or high risk of bias. The extrinsic motivators that seem to be more useful are "Reminders" and "Peer-support", but more studies are needed, namely well designed RCTs, homogeneity in BMI measure and extrinsic motivators definitions, and longer duration to better understand long-term impact of extrinsic motivators on weight management success.