Final answer:
Low-fat or nonfat milk should not be given routinely to a child until after the age of 2 years, as infants require higher fat content for development and whole cow's milk is difficult for them to digest.
Step-by-step explanation:
The student's question about when to start giving low-fat or nonfat milk to a child pertains to dietary recommendations for pediatric health. Based on collective data and recommendations, such as the information represented in Table 28.3, it is advised that low-fat or nonfat milk should not be given routinely to a child until after the age of 2 years. Before this age, children require the higher fat content found in breast milk or formula to support their rapid growth and brain development.
Whole cow's milk is also not recommended for infants due to its composition which is difficult for an infant to digest, particularly because it contains proteins and minerals that are challenging for an infant's immature digestive system to metabolize.
After the age of 2, children can gradually transition to low-fat or nonfat milk products, which provide necessary nutrients such as calcium, protein, and vitamins without the extra fat and calories found in whole milk.