Amino acids are the building blocks for protein. There are about twenty amino acids; nine of them are essential, meaning our bodies cannot produce them on their own. These nine essential amino acids need to be provided through our daily diet: histidine, isoleucine, leucine. lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Animal protein contains all of these essential amino acids making them complete proteins. Some plant foods are also complete proteins – namely quinoa, amaranth, buckwheat, spirulina, hemp seeds, and chia seeds. As a group plant foods provide all of these essential amino acids; however, most individual plant foods are considered incomplete because they don't contain all nine.