Recent studies continue to point out the critical nature of a patient's nutritional status in helping to determine important health outcomes in pediatrics. We review recent data concerning the composition of breast milk and its adequacy to support infant growth in the first six months of life, as well as trials that support breastfeeding as an important method to delay or reduce the incidence of atopic diseases such as eczema, allergies, and asthma. Studies have also been published that show how physician education and training about breastfeeding can be optimized. Studies showing how nutritional status is measured (using standard anthropometric techniques as well as more modern measures of basal metabolic rate) are highlighted, as well as the role of micronutrient supplementation of patients with the human immunodeficiency virus infection and diarrheal diseases.