Body composition reference charts for infants from birth to 24 months: Multi-center infant body composition reference study

Background: Body composition assessment in the first 2 y of life provides important insights for child nutrition and health. The application and interpretation of body composition data in infants and young children has been challenged by a lack of global reference data. Objective: To develop body composition reference charts from 0-6 mo based on air displacement plethysmography (ADP) and 3-24 mo based on total body water (TBW) by deuterium dilution (DD). Method: Body composition was assessed by ADP in infants aged 0-6 mo from Australia, India and South Africa. TBW using DD was assessed for infants aged 3 to 24 mo from Brazil, Pakistan, South Africa and Sri Lanka. Reference charts and centiles were constructed for body composition using the lambda-mu-sigma method (LMS). Results: Sex-specific reference charts were produced for fat mass index (FMI), fat-free mass index (FFMI), and percent fat mass (%FM) for 0-6 mo (n = 470 infants; 1,899 observations) and 3-24 mo (n = 1,026 infants; 3,690 observations). When compared to other available references, there were observable differences but similar patterns in trajectories of FMI, FFMI and %FM. Conclusion: These reference charts will strengthen the interpretation and understanding of body composition in infants across the first 24 mo of life.