12-year-old children had better choose full-fat milk powder, because full-fat milk powder also contains amino acids needed by human body, and is rich in vitamin D and calcium, which can promote the growth and development of human body, and tryptophan and trace elements such as calcium, magnesium and potassium contained in milk powder are conducive to promoting the baby's bone development and improving the quality of sleep, and because the digestive system of 12-year-old children is relatively mature, they can fully absorb the whole-fat milk powder. Therefore, whole milk powder is suitable for older children.