A method of reducing the accumulation of fat mass in a neonatal human infant at risk thereof which method comprises administering to the infant during at least a part of the neonatal period a therapeutic amount of a nutritional composition comprising proteins in an amount such that the composition contains more than 2.4 g of protein per 100 kcal. As weight gain during the first week of life has been associated with overweight in adulthood, this may offer a method of reducing the risk of developing obesity in later life. Also claimed is the administration of DHA to the mother during gestation period.