CanChildrenCatchupfromtheConsequencesof Undernourishment?EvidencefromChildLinear Growth,DevelopmentalEpigenetics,andBrainand NeurocognitiveDevelopment

Abstract

Recovery from nutritionally induced height deficits continues to garner attention. The current literature on catch-up growth, however, has 2importantlimitations:wide-rangingdefinitionsofcatch-upgrowthareused,anditremainsunclearwhetherchildrencanrecoverfromthebroader consequencesofundernutrition.Weaddressedtheseshortcomingsbyreviewingtheliteratureonthecriteriaforcatch-upinlineargrowthandon thepotentialtorecoverfromundernutritionearlyinlifein3domains:lineargrowth,developmentalepigenetics,andchildbrainandneurocognitive development.Fourcriteriamustbemettodemonstratecatch-upgrowthinheight:afteraperiodinwhichagrowth-inhibitingcondition(criterion 1) causes a reductionin linear growth velocity (criterion2), alleviation of the inhibiting condition(criterion3) leads to higher-than-normal velocity (criterion 4). Accordingly, studies that are observational, do not use absolute height, or have no alleviation of an inhibiting condition cannot be used to establish catch-up growth. Adoption and foster care, which provide dramatic improvements in children’s living conditions not typically attained in nutrition interventions, led to some (but incomplete) recovery in linear growth and brain and neurocognitive development. Maternal nutrition around the time of conception was shown to have long-term (potentially permanent) effects on DNA methylation in the offspring. Undernourishment early in life may thus have profound irreversible effects. Scientific, program, and policy efforts should focus on preventing maternalandchildundernutritionratherthanoncorrectingitsconsequencesorattemptingtoprovetheycanbecorrected