Results. After controlling for neonate age at time of testing, significant differences were found between groups for %fat (12.5 +/- 4.2% vs. 13.6 +/- 4.3%; P ≤ 0.0001), fat mass (414.1 +/- 264.2 g vs. 448.3 +/- 262.2 g; P ≤ 0.05) and fat-free mass (3310.5 +/- 344.6 g vs. 3162.2 +/- 343.4 g; P ≤ 0.05), with no significant differences between birth length (50.7 +/- 2.6 cm vs. 49.6 +/- 2.6 cm; P = 0.08) or birth weight (3433.0 +/- 396.3 g vs. 3368.0 +/- 399.6 g; P = 0.44).

Objective. The purpose of this study was to compare body weight and composition (%fat, fat mass, and fat-free mass) in neonates born to mothers with a normal pre-gravid BMI (< 25 kg/m2) versus neonates born to mothers with an overweight/obese pre-gravid BMI (≥ 25 kg/m2).

Study design. Seventy-two neonates (33 from normal mothers and 39 from overweight/obese mothers) of singleton pregnancies with normal glucose tolerance had their body weight and body composition assessed by air-displacement plethysmography.

Conclusions. Neonates born to mothers who have a normal BMI have significantly less total and relative fat, and more fat-free mass than neonates born to overweight/obese mothers. Though preliminary, these data suggest that the antecedents of future disease risk (e.g. cardiovascular disease, diabetes, and obesity) occur early in life.