Infant growth and breast-feeding Dear Sir:

In a recent article on reference data for weight and length increments from 1 to 12 mo of age, Roche et al (1) stated that in evaluating the growth of individual in-fants it is important to consider gestational age, birth weight and length, and parental size, “but it is less impor-tant to consider whether the infant is breast-fed or for-mula-fed. ” We disagree with this comment on the basis of longitudinal data we collected as part of the Davis Area Research on Lactation, Infant Nutrition and Growth (DARLING) study (2). Breast-fed infants for the DARLING study were selected iftheir mothers intended breast milk to be the sole source of milk for 12 mo. Formula-fed infants, still under recruitment, are selected to match the breast-fed cohort in birth weight and sex and parental socioeconomic status, height, and weight