Protein belongs to a class of nutrients called macronutrients. At 4 calories per gram, protein serves as a significant source of energy. The protein in your child's diet also performs several other important functions. In order to ensure that your child stays healthy, it is important to provide adequate amounts of protein each day.
Functions of Protein
Protein is a major component of your muscles, organs and skin. The protein in your diet also helps your body repair cells and make new cells. This is especially important for children, because children are constantly going through periods of growth and development. Protein also allows for proper wound healing and helps the body maintain fluid and acid-base balance.
Protein recommendations differ based on your child's age. Healthy toddlers between the ages of 1 and 3 need 0.55 grams of protein per pound of body weight. For a toddler weighing 30 pounds this translates to 16.5 grams of protein per day. As a child increases in age, protein needs decrease. Children between 4 and 6 need 0.5 grams of protein per pound of body weight so a 45-pound 5-year-old requires 22.5 grams of protein. Children between 7 and 14 require 0.45 grams of protein per body weight. For a 12-year-old weighing 90 pounds, this translates to 40.5 grams of protein daily.
Types of Protein
Proteins are made up of substances called amino acids. Of the 22 total amino acids, nine of them are essential, which means you must obtain them through your diet because your body cannot make them. Protein is divided into two types based on its amino acid sequence: complete and incomplete. Complete proteins contain all of the essential amino acids as well as some of the nonessential amino acids. Incomplete proteins are missing one or more of the essential amino acids.
It is important that the protein in your child's diet provide all of the essential amino acids. Animal proteins, like meat, eggs, dairy, are considered complete proteins. If your child consumes these protein sources regularly, he will consume all of the amino acids. Some plant foods -- such as hemp seeds, soy and quinoa -- also contain complete protein.
In general, plant proteins, such as nuts, beans, rice and whole grains, are classified as incomplete proteins. While these proteins do not provide all of the essential amino acids, eating two incomplete proteins together or in the course of a day, such as peanut butter and whole grain bread, can create a complete protein. This is called protein combining.