 In fact, the American Dietetic Association states that complementary proteins do not need to be consumed at the same meal and plant proteins can meet all requirements.It is however indeed possible for one to develop an amino acid deficiency if they, for example, ate solely rice and in quantities limited to that necessary to meet caloric intake needs.To avoid such a deficiency, either a complementary food high in the limiting amino acid (such as legumes which are high in lysine, in the case of rice) or quantities of rice greater than that necessary to meet caloric intake needs would be required.