How Much Protein do You need?
A healthy adult is estimated to need around 40 to 65 grams of protein per day. If this is not provided in the food you eat, your body will begin to break down muscle and other tissues to obtain the amino acids it needs. Inadequate intake and digestion of amino acids from protein can lead to stunting, poor muscle formation, thin and fragile hair, skin lesions, a poorly functioning immune system, and many other symptoms.
In plant and animal foods, the amino acids you need are mainly provided in the form of large protein molecules that require all aspects of protein digestion—denaturation in the stomach and protease action in the intestines—before absorption. Free amino acids, which require no processing by the body before absorption, may also be present but are generally not found in large amounts.
In processed foods, protein is sometimes provided as hydrolyzed protein, which means it has been chemically cut into smaller chains from two to 200 amino acids called peptides. These peptide fragments may be easier for your body to digest; that is, they may not need to be denatured in the stomach, but are still too large for direct absorption and must be digested in the intestine. Some specially produced foods for hospital or healthcare use are made of elemental amino acids; these products provide the amino acids themselves and require no digestion before absorption.