INTRODUCTION: Behavioural interventions in early life appear to show some effect in reducing childhood overweight and obesity. However, uncertainty remains regarding their overall effectiveness, and whether effectiveness differs among key subgroups. These evidence gaps have prompted an increase in very early childhood obesity prevention trials worldwide. Combining the individual participant data (IPD) from these trials will enhance statistical power to determine overall effectiveness and enable examination of individual and trial-level subgroups. We present a protocol for a systematic review with IPD meta-analysis to evaluate the effectiveness of obesity prevention interventions commencing antenatally or in the first year after birth, and to explore whether there are differential effects among key subgroups.

METHODS AND ANALYSIS: Systematic searches of Medline, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycInfo and trial registries for all ongoing and completed randomised controlled trials evaluating behavioural interventions for the prevention of early childhood obesity have been completed up to March 2021 and will be updated annually to include additional trials. Eligible trialists will be asked to share their IPD; if unavailable, aggregate data will be used where possible. An IPD meta-analysis and a nested prospective meta-analysis will be performed using methodologies recommended by the Cochrane Collaboration. The primary outcome will be body mass index z-score at age 24±6 months using WHO Growth Standards, and effect differences will be explored among prespecified individual and trial-level subgroups. Secondary outcomes include other child weight-related measures, infant feeding, dietary intake, physical activity, sedentary behaviours, sleep, parenting measures and adverse events.

ETHICS AND DISSEMINATION: Approved by The University of Sydney Human Research Ethics Committee (2020/273) and Flinders University Social and Behavioural Research Ethics Committee (HREC CIA2133-1). Results will be relevant to clinicians, child health services, researchers, policy-makers and families, and will be disseminated via publications, presentations and media releases.


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Published in BMJ Open, v. 12, issue 1, 048166.

© Author(s) (or their employer(s)) 2021

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: https://creativecommons.org/licenses/by-nc/4.0/.

The first 20 authors and the author from the University of Kentucky are shown on the author list above. Please refer to the downloaded document for the complete author list.

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This work was supported by the Australian National Health and Medical Research Council (NHMRC) Ideas Grant TOPCHILD (Transforming Obesity Prevention for CHILDren): Looking into the black box of interventions (GNT1186363). Funders had no role in developing this protocol. Individual authors declare the following funding: ALT reports funding from NIH R01HD073237; AML reports funding from NIH National Center for Advancing Translational Science through grant # UL1TR000117 and UL1TR001998; BJT reports funding from Health Research Council of New Zealand; CGA reports funding from The PepsiCo Foundation; CP reports funding from National Institutes of Health, Robert Wood Johnson Foundation, World Health Organization, US Department of Agriculture; COS reports funding from University of Cincinnati University Research Council; DAOC is supported by an Australian National Health and Medical Research Council (NHMRC) Translating Research into Practice Fellowship (APP1168749); EO reports the PROBIT study was supported by grant MOP-53155 from the Canadian Institutes of Health Research and grant R01 HD050758 from the US National Institutes of Health; IMP reports funding from grant R01DK088244 from the United States National Institute of Diabetes and Digestive and Kidney Diseases; JCB reports funding from US Department of Agriculture; JKL and LTK reports funding from Fonds NutsOhra awarded (100.939); JSS reports funding from NIH NIDDK, NIH NHLBI, PCORI; JLT is an employee of USDA ARS and the Agency did fund the Delta Healthy Sprouts Trial (Project 6401-5300-003-00D); KdlH reports funding from 1R01HD092483-01 (MPI: de la Haye, Salvy), NIH/NICHD; KDH is supported by an Australian Research Council Future Fellowship (FT130100637); LMW reports funding from NHMRC (#393112; #1003780; #1169823); LW is supported by a NHMRC Career Development and NHF Future Leader Fellowship; MB reports HAPPY was funded by a UK NIHR Programme Grant for Applied Research (project number RP-PG-0407-10044); MCR reports The Baby Act Trial was sponsored by the Center for Collaborative Research in Health Disparities under grant U54 MD007600 of the National Institute on Minority Health and Health Disparities from the National Institutes of Health; MJM reports funding from USDA AFRI 2011-68001-30207; NCØ reports their original study was partly funded by the Norwegian Women's Public Health Association, who had no influence on any part of the study design, implementation and evaluation; RKG is a Chief Investigator on the Early Prevention of Obesity in Childhood, NHMRC Centre for Research Excellence (1101675); RSG is supported by the National Institute of Food and Agriculture/US Department of Agriculture, award number 2011-68001-30207, and the National Institutes of Health/National Institute of Child Health and Human Development through a K23 Mentored Patient-Oriented Research Career Development Award (K23HD081077; principal investigator: Rachel S. Gross); RL reports funding from UK NPRI (National Prevention Research Initiative), MRC PHIND (Public Health Intervention Development programme); SLOR reports funding from European Unions Horizon 2020 Research and Innovation Programme (Grant Agreement no. 847984) and Australia National Health and Medical Research Council (NHMRC) (Grant application no. APP1194234); S-JS reports funding from NIMHD U54MD000502 (MPI: Salvy & Dutton Project #2), NICHD R01HD092483 (MPI: Salvy & de la Haye); SA-F is a co-investigator on the current INSIGHT grant which follows participants to ages 6 and 9: NIH 2R01DK088244; ABP-E reports the SPOON program in Guatemala is funded by the Inter-American Development Bank with donations of The Government of Japan and The PepsiCo Foundation.