Proteins consist of amino acids. The body can break down and digest amino acids depending on the length thereof. The shorter the amino acid chain, the faster the absorption and build-in in the muscle.
There are numerous protein sources of which protein powders and bars are made. The quality of the protein is assessed by the biological value (BV). This number shows what percentage of the protein can be utilized by the body in relation to egg whites' 100 value. The higher the biological value, the better the protein the be absorbed and utilized. Whey proteins have the highest BV of 104. Breast milk has a BV of 95, therefore most baby formulas are whey protein-based.