Figure 30.3: A Common Food Combination Provides All Eight Essential Amino Acids All around the world, cultures exist in which corn and beans are major parts of the daily diet. We mimic this diet when we snack on tortilla chips and bean dip. Eaten together, these two foods provide all the essential amino acids required by adult humans. (Corn by itself often does not provide enough lysine or isoleucine, and beans often do not provide enough methionine or tryptophan.) When two or more foods must be eaten to get all eight essential amino acids, it is important to eat the foods at about the same time.