Effectiveness of Participatory Research Interventions on Obesity and Obesity-Related Behaviors in Adolescents: A Systematic Review and Meta-analysis.

Context: Adolescence is an optimal period to promote healthy lifestyles because behavior patterns are established in this stage. It has been suggested that engaging youth increases the effectiveness of interventions, but an overview is lacking.

Objective: This study aims to evaluate the effectiveness of participatory research (PR) interventions, where adolescents (11-18 years old) from high-income countries had a significant role in the intervention development and/or delivery, compared with no (PR) intervention control groups on obesity-related outcomes and healthy lifestyle behaviors (HLBs).

Data sources: Eight databases (Embase, Medline ALL, Web of Science Core Collection, PsycINFO, ERIC, CINAHL, Scopus, and Cochrane Central Register of Controlled Trials) and Google Scholar were searched from 1990 to 2024 for randomized controlled trials (RCTs) and non-RCTs (in English).

Data extraction: Two researchers independently performed the data extraction and risk-of-bias assessment.

Data analysis: Sixteen studies were included and outcomes have been narratively described. Seven studies evaluated youth-led interventions, 3 studies evaluated co-created interventions, and 6 studies evaluated the combination of both. Six studies focused on physical activity (PA), 2 on nutrition, and 8 on a combination of PA, nutrition, and/or obesity-related outcomes. Ten studies presented at least 1 significant effect on PA, nutrition, or obesity-related outcomes in favor of the intervention group. Additionally, 12 studies were pooled in a meta-analysis. Whereas a small desired effect was found for fruit consumption, a small undesired effect was found for vegetable consumption. The pooled analysis found no significant effects on moderate-vigorous PA, total PA, and PA self-efficacy.

Conclusion: We found some evidence that youth empowerment in research may have positive effects on obesity-related HLBs, specifically an increased fruit consumption. However, the overall evidence was inconclusive due to limited studies and the heterogeneity of the studies included. This overview may guide future public health interventions that aim to engage and empower adolescents.

Systematic review registration: PROSPERO registration Nº CRD42021254135.