Body Composition in Young Ethiopian Infants: Reference Data Obtained by Air-Displacement Plethysmography

Abstract

Background Early growth is rarely described in terms of fat mass (FM) and fat free mass (FFM), but this is particularly valuable for low-income country populations where impaired fetal and infant growth is common and relates to disease risk in both childhood and adulthood.

Objective To provide reference data for FM and FFM from birth to the age of 6 months from an African population, and compare them with reference data from a western population

Design Ethiopian infants were followed from birth to the age of 6 months and measured FM and FFM at birth, 6, 10, 14, 18 and 26 weeks of age using air-displacement plethysmography (ADP).

Results Among 255 infants we found a pattern of increasing FM and FFM from birth to the age of 6 months. FM gain progressed in a logarithmic shaped curve whereas FFM was gained in a linear shaped curve. Boys had more FFM than girls throughout the 6 months (p<0.01). The FM and FFM accretion patterns differ from those described in a western population. Ethiopian infants were smaller in fat and fat-free mass at birth but increased their fat to lean ratio during early infancy growth. Boys in the present study weigh less than those from a western population, but due to deficits in FFM only.

Conclusions These reference data suggest a distinct pattern of increased fat to lean ratio in early infancy in an African population undergoing nutrition transition. These data may be used as future reference.