Your brain runs on glucose. Without it, you'd have difficulty handling "4 + 4." Fortunately, legumes provide the glucose necessary to focus on the task at hand and maintain that concentration. This happens with the help of the fiber that legumes also contain.
Fiber prevents glucose from being soaked up too fast. Instead of an energy spike, you get a consistent, sustained flow of fuel [source: Moreno]. It's hard to get bored with legumes since they come in so many varieties. You can snack on edamame, make peas a side dish for your healthy meal or add beans to a salad.