Quinoa vs. Brown Rice: Nutritional Comparison. When comparing quinoa with brown rice, quinoa wins every time. Quinoa has more fiber, a lower glycemic load, and substantially more amino acids.Quinoa is one of the rare complete-protein foods, meaning it contains all essential amino acids needed for growth, cellular repair, and energy production.uinoa vs. Brown Rice: Nutritional Comparison. When comparing quinoa with brown rice, quinoa wins every time. Quinoa has more fiber, a lower glycemic load, and substantially more amino acids.