A scoping review of infant body composition (0–24 months) assessed by deuterium dilution

CONTEXT: The deuterium dilution technique is applicable across the 0-24 month age range in diverse resource settings. No structured review has previously mapped the scope of its use in this population. OBJECTIVE: This scoping review was limited to mapping infant body composition studies (0-24 months) using deuterium dilution, describing methodological approaches, identifying contexts of applications, and highlighting evidence gaps. METHODS: A structured literature search was conducted across four databases with citation tracking, following prisma-ScR guidelines. RESULTS: Twenty-four studies from approximately 18-20 distinct cohorts across six continents were included from 1,078 identified records. Substantial heterogeneity was documented in every protocol element: dose, equilibration time, analytical platform, correction factor for non-aqueous exchange (unreported in approximately one-third of studies), and hydration model. This heterogeneity prevents direct comparison of fat mass and fat-free mass values across studies, precluding meta-analytic synthesis. Key gaps include the near-absence of data in preterm infants (one study), small for gestational age (SGA) or intrauterine growth restriction (IUGR) classification in only three of 24 studies, and incomplete breastfeeding documentation. CONCLUSION: This review maps a growing but methodologically heterogeneous literature. Standardised protocol reporting, dedicated preterm and SGA studies, and longitudinal designs linking early body composition to later outcomes are research priorities.