When your mom told you to eat your peas, she knew what she was talking about. Peas flaunt twice the protein of most vegetables, so they're the ideal substitute for fattier protein choices, providing an excellent strategy for controlling your fat intake. Green peas are legumes, except they're eaten before they mature. As with all legumes, they're chock-full of nutrients and low in calories. Of the myriad of nutrients peas provide iron is particularly important since it's hard to find non-animal foods with much of this blood-building nutrient.