Breastfeeding and determinants of adult body composition: a prospective study from birth to young adulthood.

BACKGROUND: The impact of breastfeeding on adult body composition is controversial. We evaluated effects of lifestyle and childhood-related factors, including infant feeding, on adult body composition. METHODS: We determined total body and trunk fat and lean mass by densitometry in 158 adults who were born full-term and prospectively followed from birth to the age of 32 years. Data on various factors, extending from infancy to adulthood, with potential effect on body composition, were recorded. RESULTS: Scapular skinfold thickness at 12 months correlated with adult trunk (R = 0.22, p = 0.005) and body fat percentage (R = 0.18, p = 0.023). In linear regression analysis, current physical activity (R = -0.33, p < 0.001) and maternal BMI (R = 0.28, p = 0.002) were associated with adult body fat percentage. Gender (R = 0.78, p < 0.001) and weight gain during infancy (R = 0.147, p = 0.008) were associated with adult lean mass. In the analysis of covariance, prolonged breastfeeding tended to lead to lower fat percentage in adulthood, but no direct association with the duration of breastfeeding and adult body composition was confirmed. CONCLUSIONS: Current physical activity, growth in infancy, gender and maternal BMI influence adult body composition. Breastfeeding has an indirect influence on adult body fat accumulation by affecting growth and body adiposity in infancy.