Abstract
Although we have found that, at 7 years of age, children who were exclusively breast-fed in the first 3 months of life are significantly taller and slightly heavier than those exclusively formula-fed, correction for a variety of other familial factors can explain most of the differences. The breast-fed were longer at birth, had taller mothers, and came from families of higher socioeconomic status, although the last appears to act via maternal stature. There was no difference between the groups at age 7 in skeletal maturity, nor in fatness as measured by combined triceps plus subscapular fatfold. Apparent associations between the method of infant feeding and findings in later childhood must thus be interpreted with caution, since they may reflect differences between the characteristics of families choosing different methods of feeding rather than an effect of the feeding method itself.