No matter what your snack choice is -- sweet or savory -- we all head for something when our stomachs start to rumble. The best snacks are about 100 calories. Beyond counting calories, though, you should look for what's going to be the healthiest choice -- meaning what's going to provide the most nutrition -- like nuts and seeds, fruits and veggies as well as low-fat dairy and whole grains. So where does a candy bar or a bag of chips fit into that? Test your snack knowledge to find out.