Rapid weight gain during infancy and subsequent adiposity: a systematic review and meta-analysis of evidence

The contribution of rapid weight gain (RWG) during infancy to later adiposity has received considerable investigation. The present systematic review and meta-analysis aimed to update the literature on association between RWG and subsequent adiposity outcomes. Electronic searches were undertaken in EMBASE, MEDLINE, psycINFO, PubMed and ScienceDirect. Studies that examined the associations between RWG (a change in weight z-scores > 0.67) during infancy (from birth to age 2 years) and subsequent adiposity outcomes were included. Random effects meta-analysis was conducted to obtain the weighted-pooled estimates of the odds of overweight/obesity for those with RWG. Seventeen studies were eligible for inclusion with the majority of studies (15/17) being of high/acceptable quality and reporting positive associations between RWG during infancy and later adiposity outcomes. RWG in infancy was associated with overweight/obesity from childhood to adulthood (pooled odds ratio = 3.66, 95% confidence interval: 2.59-5.17, I-2 > 75%). Subgroup analyses revealed that RWG during infancy was associated with higher odds of overweight/obesity in childhood than in adulthood, and RWG from birth to 1 year was associated with higher odds of overweight/obesity than RWG from birth to 2 years. The present study supports that RWG during infancy is a significant predictor of adiposity in later life.