Impact of a participatory research intervention based on a citizen science approach on snacking consumption in European adolescents from deprived areas: a cluster randomised control trial of the SEEDS project.

BACKGROUND: Improving adolescent diets requires promising interventions, best developed through participatory research like Citizen Science (CS). The present study aimed to assess the impact of a CS intervention on the consumption of healthy and unhealthy snacking choices for adolescents living in deprived areas and the influence of gender, age, and socioeconomic status (SES) in snacking behaviour. METHODS: SEEDS is a cluster-randomised controlled trial (c-RCT) in four European countries, with 26 high schools randomized to intervention (IG) or control (CG) groups. The analysis included 1,208 adolescents aged 13–15 (IG = 589, CG = 619). Adolescents from IG in each country co-created a 6-month intervention on healthy snacking and physical activity. Snack consumption was the main outcome, assessed via the Health Behaviour in School-Aged Children questionnaire. General Linear Models analysed intervention impact and the influence of gender, sex, and SES. RESULTS: IG adolescents showed higher odds than CG of daily fruit consumption [OR (95% CI) = 1.44 (0.03–2.02)], daily water consumption [OR (95% CI) = 1.89 (1.30 -2.77)] during school, and daily vegetable consumption [OR (95% CI) = 1.36 (1.01–1.82)] outside school hours. IG adolescents showed a higher odds of occasional cake/biscuits consumption [OR (95 CI) = 1.55 (1.14–2.13); OR (95% CI) = 1.82 (1.39–2.39)] and occasional juices/smoothies’ consumption [OR (95 CI) = 1.57 (1.15–2.16); OR (95% CI) = 1.33 (1.03–1.71)] than CG during and outside school. No effects were found for other snacks. CONCLUSIONS: A CS intervention, co-created by adolescents, improved snacking in and out of school, though promoting healthy snacking remains challenging and should be a focus for future efforts. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05002049 (URL: https://clinicaltrials.gov/study/NCT05002049?cond=NCT05002049&rank=1 ); Date of registration: July 15, 2021.