How early dietary factors modify the effect of rapid weight gain in infancy on subsequent body-composition development in term children whose birth weight was appropriate for gestational age.

BACKGROUND It is not clear whether the adverse effects of rapid weight gain in infancy are modified by nutrition during the first 2 y of life in term children whose birth weight was appropriate for gestational age (AGA). OBJECTIVE We examined the interaction between rapid weight gain and nutrition in infancy and early childhood and their effect on body fat percentage (BF%) trajectories between 2 and 5 y of age. DESIGN The study population comprised 249 (51.4% female) term AGA participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study, for whom repeated anthropometric measurements until 5 y of age and information on breastfeeding status and on diet at 12 and 18-24 mo of age were available. RESULTS Multilevel model analyses showed that, among rapid growers, those who had been fully breastfed for > or =4 mo had a lower BF% at 2 y of age than did those who had not been fully breastfed for > or =4 mo (beta +/- SE: -1.53 +/- 0.59%; P = 0.009). This difference persisted until 5 y. Furthermore, those rapid growers who had a consistently high fat intake at both 12 and 18-24 mo did not show the expected physiologic decrease in BF% between 2 and 5 y seen in those rapid growers with an inconsistent or consistently low fat intake at these time points (0.73 +/- 0.26%/y; P = 0.006). CONCLUSIONS Among rapid growers, full breastfeeding for > or =4 mo is protective against a high BF% at 2 y of age, whereas a consistently high fat intake in the second year of life "inhibits" the physiologic decrease in BF% between 2 and 5 y.