Corn is the seed of a plant, and thus, a grain, not a vegetable. It's a confusion of flavor and texture, because they're awfully sweet, soft seeds. But just like tomatoes are a fruit because they carry their seeds inside, flavors don't change nutrition. Don't think you're loading up on veggies when you eat corn: it's another grain just like wheat, rice and barley. Even popped.
Popcorn falls into the vegetable food group. Popcorn is made from dry corn kernels, so this qualifies first as a vegetable. Now if you add butter to it, then you have also added another food group. The food group butter belongs to, is the fat/oil food group.
popcorn lies in the Vegetable category because as most of u know it is from dried up kernels a.k.a.corn.And if your family likes popcorn and they didn't know it was a vegetable they would probably not be shocked. but it is the most healthy snack!