Essential amino acids are organic compounds that your body needs to function, but cannot make on its own. You have to get them from the foods you eat. There are nine essential amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
Foods that contain all nine essential amino acids are called complete proteins.
These foods include animal products such as meat, eggs, poultry, fish, and dairy. Some plant foods, such as soy products (edamame and tofu), quinoa, and buckwheat, are also complete proteins.
Foods that contain some but not all the essential amino acids are called incomplete proteins. These foods include grains, beans, nuts, seeds, and vegetables. You can combine different incomplete proteins to get all the essential amino acids you need. For example, rice and beans, peanut butter and bread, or hummus and pita are some common combinations of incomplete proteins.
Essential amino acids play many important roles in your body, such as building proteins, hormones, and neurotransmitters. They can also enhance your athletic performance, reduce muscle breakdown, and improve your liver function. Therefore, it is important to eat a balanced diet that provides enough essential amino acids for your health.