Body Composition Measurement in Infants

Crown-to-heel length was measured in duplicate using a Seca 416 infantometer (Seca, Hamburg, Germany) with both measures being within 0.1 cm. Nude body weight was measured in duplicate with a Seca 728 scale (Seca, Hamburg, Germany) with both measures being within 10 g. On the rare occasion these measures exceeded the criteria set forth, a third measure was obtained and the two closest values averaged. Weight-for-length z-scores were calculated using World Health Organization data. Total adiposity (% fat), fat mass (g), lean mass (g), bone mineral density (g/cm²), and bone mineral content (g) were collected using a Lunar iDXA (General Electric, Fairfield, CT, USA) scanner as described previously [12 (link)]. During the scan, the infant wore only a diaper and was swaddled in a light blanket. The principal investigator (DAF) positioned all infants and performed subsequent scan analyses.