What is a small, round, gluten-free grain that is recognized as a complete protein?

Quinoa is the small, round, gluten-free grain that is recognized as a complete protein. It contains all nine essential amino acids that the human body needs, which is a key characteristic of a complete protein. This makes quinoa particularly valuable for vegetarians and vegans who seek plant-based sources of protein. In addition to its complete protein profile, quinoa is also rich in fiber, vitamins, and minerals, which contribute to its status as a superfood in many diets.

In contrast, while buckwheat is also gluten-free, it is not a complete protein because it lacks some essential amino acids. Rice and barley, on the other hand, do not qualify as complete proteins either. Rice is primarily low in lysine, an essential amino acid, and barley contains gluten, thus not fitting the gluten-free criteria. These distinctions underscore the importance of recognizing quinoa as the correct answer regarding its nutritional properties.