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.