To Örebro University

Introduction: Complementary feeding (CF) is defined as the period from when exclusive breast milk and formula are no longer sufficient for meeting the infant's nutritional needs. The CF period occurs from birth to 23 months of age. Though the recommended guidelines for introducing CF is from around 6 months of age, data indicates that some infants are introduced to food earlier than 6 months which can predispose children to obesity and overweight. Obesity in ethnic minority groups (EMG) is higher than their native counterparts and often tracks into adulthood. Hence, our aim was to conduct a systematic review and meta-analysis on the available literature to identify the risk of childhood overweight/obesity associated with CF practices concerning their timing, as well as the frequency and type of CF food introduced. We focused specifically on EMG children living in high-income countries.

Methods and analysis: A methodological literature search surrounding childhood obesity and overweight (COO) risk associated with CF practices will be conducted in May 2021 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines. The following academic databases will be methodologically searched: PubMed, EMBASE, PsycINFO, CINAHL, SCOPUS, Cochrane Library and the WHO Global Index Medicus. Three independent researchers will be involved in independent screening and review the included articles based on the predefined inclusion and exclusion criteria. Where conflicts arise during the screening process, it will be resolved through discourse until a consensus is reached. Information on CF practices and anthropometric measurements will be extracted to ascertain the risk of COO. For this study, WHO body mass index for age and sex percentiles, Centers for Disease Control and Prevention classification and other recognised country-specific classifications will be utilised for the outcome.

Ethics and dissemination: Formal ethical approval is not needed as the results will be drawn from currently available published literature. Outcomes of the review will be shared through peer-reviewed publications.

PROSPERO registration number: CRD42021246029.