Effects of animal source foods, with emphasis on milk, in the diet of children in low-income countries.

This review evaluates evidence for benefits of including animal source foods (ASF) in the diets of children in developing countries. In observational studies, a higher usual intake of ASF in such countries is associated with better growth, status of some micronutrients, cognitive performance, motor development and activity. Only three randomized trials supplemented children with milk and compared outcomes with a nonintervention control group. Both height and weight growth were improved, although in Kenya height was increased only in younger schoolers who were stunted at baseline. Meat supplements have been evaluated in only two randomized controlled trials, in Kenya and Guatemala (mean baseline age 8 years and 1 year, respectively); growth was no better than in an equicaloric control group. Meat improved cognitive function and activity in Kenya; milk was less effective than meat for improving cognitive function and physical activity, perhaps due to its lower content of iron, zinc, or riboflavin. Meat and especially cow's milk are excellent sources of vitamin B(12), a micronutrient commonly deficient in populations which consume low amounts of ASF. Other micronutrients such as iron have been added to cow's milk and resulted in improved nutritional outcomes for children.