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.