Infants are measured by a research midwife within 10 days of birth (at randomisation), 8, 16 and 26 weeks of age. At randomisation consent from the mother is taken and information collected about the pregnancy, social, demographic and medical data. At this and each further visit anthropometric measurements including skinfolds will be collected in addition to blood pressure and bio-electrical impedence at six months. A sub-sample of infants will have their body composition assessed by deuterium labelled water at six months. Data on health, weaning diets and bowel function are also collected at each visit.