In discussions about the evolution of human diet, a great deal of attention has focused on the impact of different diets on adult diseases, but there has been less examination of how diets affect child nutrition and health. If nutritional and health status are measured by early childhood physical growth and mortality, none of the diets of "traditional" living human populations would appear to be optimal since all of them are associated with growth delays and high mortality. These negative consequences are certainly not entirely the result of the actual composition of the diet, but are also caused by factors such as food shortages, poor sanitary conditions, and lack of health care. The extent to which diets contribute to poor child health should be an important consideration in any debate about the evolution of human diet.