Banana a day won't give you enough potassium

It takes more than a banana to get all the potassium you need each day. Medical experts recommend 4,700 milligrams of potassium. That banana only has 420mg.

Jayne Hurley, senior nutritionist with the Center for Science in the Public Interest, says that's why you need to eat more fruit and veggies.

"Potassium may be the reason that vegetables help lower blood pressure and the risk of stroke," she said.

Here are the veggies with the most potassium: sweet potato, lima beans, spinach, Swiss chard and Portobello mushrooms.

Hurley says studies have shown that people who eat a lot of vegetables have a lower risk for type 2 diabetes.

"The ones that may be particularly helpful in lower the risk are things like spinach, Swiss chard, lima beans, Arugula and peas."

Something else that's lacking in the American diet -- fiber, which helps prevent heart disease, stroke and diabetes, as well was keep you regular.

The top five veggies for fiber are: artichoke, peas, avocado, lima beans and jicama.