Breast-fed infants are leaner than formula-fed infants at 1 y of age: The DARLING study

Anthropometric indexes from 1 to 24 mo were compared between matched cohorts of infants either breast-fed (BF, n = 46) or formula-fed (FF, n = 41) until ≥ 12 mo. Neither group received solid foods before 4 mo. Weight-for-length was significantly greater among FF infants from 7 to 24 mo. In both groups, skinfold thickness (triceps, biceps, subscapular, flank, and quadriceps) and estimated percent body fat (%FAT) increased rapidly during the first 6-8 mo and declined thereafter. At all sites except biceps, FF infants had larger skinfold thicknesses in later infancy (particularly 9-15 mo) than did BF infants; %FAT was significantly higher from 5 to 24 mo. Lower energy intake among BF infants explained the difference between groups. Maternal and infant fatness were positively correlated at 12-24 mo. Breast-milk lipid and energy concentration were unrelated to infant fatness. These results indicate that infants BF for ≥ 12 mo are leaner than their FF counterparts.