Early feeding of larger volumes of formula milk is associated with greater body weight or overweight in later infancy

BACKGROUND The relation between infant feeding and growth has been extensively evaluated, but studies examining the volume of formula milk consumption on infant growth are limited. This study aimed to examine the effects of early feeding of larger volumes of formula on growth and risk of overweight in later infancy. METHODS In total, 1093 infants were studied prospectively. Milk records collected at 3 mo of age were used to define the following 3 feeding groups: breast milk feeding (BM, no formula), lower-volume formula milk feeding (LFM, <840 ml formula/d), and higher-volume formula milk feeding (HFM, ≥840 ml formula/d). Body weight and length were measured at 3 time points of 3, 6 and 12 mo of age. RESULTS The results showed that the difference in weight and length between the HFM and BM infants was significant at 3 mo of age (P < 0.05) and continued until 12 mo of age (P < 0.001). The adjusted mean changes in weight-for-length z-scores (WLZ) and BMI-for-age z-scores (BAZ) from 3 to 6 mo of age were significantly higher in HFM and LFM group than in BM group. Two-way interactions between feeding practice and age intervals were significant for WLZ changes (P = 0.002) and BAZ changes (P = 0.017). Compared with BM-fed infants, infants fed with HFM had 1.60-fold (95% CI 1.05-2.44) higher odds of greater body weight (1SD < WLZ ≤2 SD) at the age of 6 mo and 1.55-fold (95% CI 1.01-2.37) higher odds of greater body weight and 2.13-fold (95% CI 1.03-4.38) higher odds of overweight (WLZ > 2 SD) at the age of 12 mo. CONCLUSION Feeding higher volumes of formula in early infancy is associated with greater body weight and overweight in later infancy.