An assessment of methods for measuring body composition in full-term infants: A systematic review

Background: Numerous methods are available for measuring body composition in infants, however, there is no consensus on which approach is preferred. The aim of this study was to identify one such method for a clinical and research setting. Methods: A systematic search was conducted on PubMed, Embase, and Cochrane Library to identify studies that investigated the accuracy of body composition methods in full-term infants up to 2 years of age. Results: Thirty out of 6643 identified records were included. Several anthropometric equations were investigated with inconsistent results. Dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA) showed more comparable results to those assessed by air displacement plethysmography (ADP), when applying new techniques. Few studies assessed the accuracy of quantitative magnetic resonance (QMR), isotope dilution, and near-infrared spectroscopy (NIR); nonetheless, they all performed well against reference methods. ADP showed agreement compared to deuterium dilution, 3-compartment-, and 4-compartment-models on group-level; however, there were discrepancies when compared to DXA. Conclusions: Anthropometry, DXA, BIA, and ultrasound showed varying results, highlighting the need for further research. QMR, isotope dilution, and NIR appeared promising, but evidence is limited due to few studies. ADP showed consistently small bias compared to multi-component models and isotope dilution. Impact: Accurate body composition assessment in infancy has the potential to improve prophylactic actions against obesity. There is relative consensus on the most accurate body composition assessment in pre-term infants in a research setting, however, this consensus has not been available for full-term infants until now. Measure of anthropometry performs with varying precision, suggesting very low feasibility of the method for body composition assessment. From a research perspective, air displacement plethysmography is an accurate method for measuring body composition in full-term infants. This systematic review identifies research gaps within the scientific field of infant body composition.