Body Composition Assessment in Healthy Full-term Neonates by Anthropometry, Air Displacement Plethysmography and Multiple-frequency Bio-impedance Analysis

Low birth weight and prematurity are associated with adverse metabolic outcome in adult life. Yet it remains to be determined whether this outcome is the consequence of the low birth weight per se, or of the catch up growth achieved in Neonatology units using an early, 'aggressive' nutritional management. As a matter of fact, 'aggressive' nutrition may promote fat mass, rather than lean body mass accretion. Assessment of body composition therefore is key to evaluate the efficacy of the nutritional management of these infants. Scarce data is, however, available in the literature about the body composition of healthy full-term neonates in the first few days of life.

The aim of this study is to:

1. Evaluate the feasibility and reproducibility of a safe and non invasive method of measurement of infant body composition by Air Displacement Plethysmography (PeaPod). Anthropometry and BIA will be used as the reference techniques to assess the accuracy of the PeaPod 2. Describe the body composition (fat mass, fat free mass) of healthy full-term neonates in the first few weeks of life 3. Obtain data on the total body water content of healthy full term infants from BIA.