I’d have guessed brussels sprouts or some type of green, but no, the most nutritious vegetable—accroding to the Center for Science in the Public Interest—is the sweet potato. The sweet potato contains Vitamin A (eyes), C (immunity enhancer) and potassium (aids muscle development). Sweet potatoes also contain some 10 other vitamins and minerals necessary for optimum health.
And that’s not all, sweet potatoes are slow burning sugars that give you energy without making you fat.
Dr. Bob at Men’s Journal October 2010