Body composition in full-term healthy infants measured with air displacement plethysmography at 1 and 12 weeks of age

Aim: To use Pea Pod, a device based on air displacement plethysmography, to study body composition of healthy, full-term infants born to well-nourished women with a western life-style. Methods: Body composition was assessed in 53 girls and 55 boys at 1 week (before 10 days of age) and at 12 weeks (between 77 and 91 days of age). Results: At 1 week girls contained 13.4 +/- 3.7% body fat and boys 12.5 +/- 4.0%. At 12 weeks, these figures were 26.3 +/- 4.2% (girls) and 26.4 +/- 5.1% (boys). Body fat (%) did not differ significantly between the genders. Body fat (%) at the two measurements was not correlated. At 1 week, the weight (r = 0.20, p = 0.044) and BMI (r = 0.26, p = 0.007) of the infants, but not their body fat (g, %) or fat free mass (g), correlated with BMI before pregnancy in their mothers. Conclusions: Pea Pod has potential for use in studies investigating the effect of external (i.e. nutritional status) and internal (i.e. age, gender, gestational age at birth) factors on infant body composition. This may be of value when studying relationships between the nutritional situation during early life and adult health.