Parent-focused behavioural interventions for the prevention of early childhood obesity (TOPCHILD): a systematic review and individual participant data meta-analysis

Authors: HUNTER, KYLIE - University Of Sydney; NGUYEN, DAVID - University Of Sydney; Thomson, Jessica

Submitted to: Lancet
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2025
Publication Date: 9/20/2025
Citation: Hunter, K.E., Nguyen, D., Thomson, J.L. 2025. Parent-focused behavioural interventions for the prevention of early childhood obesity (TOPCHILD): a systematic review and individual participant data meta-analysis. Lancet. 406(10509):1235-1254. https://doi.org/10.1016/S0140-6736(25)01144-4.
DOI: https://doi.org/10.1016/S0140-6736(25)01144-4

Interpretive Summary: Researchers from around the world have developed interventions to combat childhood obesity, a global health issue. To date, no comprehensive review of these worldwide interventions has been conducted to determine the effectiveness of early childhood obesity prevention programs. A systematic review of parent-focused behavioral interventions for early childhood obesity prevention was conducted. Out of 47 completed and eligible trials, 31 provided individual participant data (i.e., row-by-row data for each participant in each trial) for 28,825 children from 10 countries. Findings indicated that the interventions did not positively affect child body mass index at 24 months of age, nor did they affect select behavioral outcomes relating to diet, feeding, physical activity, and sleep. Based on this comprehensive analysis of childhood obesity prevention programs, it appears that current approaches to parent-focused behavioral interventions are not sufficient to prevent childhood obesity in young children. Hence, researchers and practitioners may need to rethink childhood obesity prevention approaches and consider combining behavioral methods with system level approaches to successfully prevent obesity in young children.

Technical Abstract: Background: Childhood obesity is a global public health issue, which has prompted governments to invest in prevention programs. This study evaluated the effectiveness of parent-focused early childhood obesity prevention interventions globally. Methods: We conducted a systematic review and individual participant data meta-analysis (PROSPERO: CRD42020177408). We searched databases and trial registries from inception until October 4, 2024, for randomised controlled trials commencing before 12 months of age examining parent-focused behavioural interventions to prevent obesity in children, compared with usual care, no intervention, or attention control. Individual participant data were checked, harmonised, and assessed for integrity and risk of bias. The primary outcome was body mass index (BMI) z-score at age 24±6 months, with 33 pre-specified behavioural and anthropometric secondary outcomes. We conducted intention-to-treat two-stage random effects meta-analysis to examine effects overall and for pre-specified subgroups. Certainty of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation. Findings: Of 19,990 identified records, 47 trials were completed and eligible. Of these, 18 assessed our primary outcome, BMI z-score. We obtained individual participant data for 17 (n=9128) out of these 18 trials (n=9383), representing 97% of eligible participants. Of these 9128 participants, 4549 (51%) were boys, 4415 (49%) girls and 164 had unknown sex. We found no evidence of an effect of interventions on BMI z-score at age 24±6 months (mean difference -0.01 [95% CI -0.08, 0.05], high certainty evidence, t2=0.01, n=6505, 2623 missing), and no evidence of effects for most secondary outcomes. Findings were robust to pre-specified sensitivity analyses (e.g. different analysis methods, missing data), and there was no evidence of differential intervention effects for pre-specified subgroups including priority populations and trial-level factors. Interpretation: These findings indicate that current parent-focused behavioural interventions are insufficient to prevent obesity at age 24±6 months. This highlights a need to re-think childhood obesity prevention approaches.