December 24, 2008
Proteins are organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. The sequence of amino acids in a protein is defined by the sequence of a gene, which is encoded in the genetic code. Higher-protein meals may help overweight and obese people burn more fat.

Proteins were first described and named by the Swedish chemist Jöns Jakob Berzelius in 1838. However, the central role of proteins in living organisms was not fully appreciated until 1926, when James B. Sumner showed that the enzyme urease was a protein. Animal protein and vegetable protein probably have the same effects on health. It's the protein package that's likely to make a difference.

Vegetable sources of protein, such as beans, nuts, and whole grains, are excellent choices, and they offer healthy fiber, vitamins and minerals. The best animal protein choices are fish and poultry.