To analyze caloric adequacy in infant feeding six months of age or under, the volume of breast milk consumed was estimated through a regression equation as proposed by Drewett. Energy adequacy was estimated according to World Health Organization guidelines for developing countries and the recommended daily allowance of the Food and Nutrition Board. A cross-sectional analysis was conducted on data from a cohort of 118 infants in a neighborhood around a health center in Campinas, São Paulo, Brazil, with home interviews by trained students. Data were gathered on social and demographic characteristics, infant feeding patterns, duration of breastfeeding, frequency of feedings, and age when breast milk substitutes were introduced. On average, weaning began early, with a 2.7-month median duration of exclusive breastfeeding. Mean breast milk volume was estimated (from frequency of feeding) as 561.0 ml, 558.9 ml and 565.5 ml for children in exclusive, predominant, and supplemented breastfeeding, respectively. Mean energy consumption was adequate for all exclusively breastfed children regardless of age and above the recommended level for infants with supplemented breastfeeding and those already weaned.