Popcorn is a carbohydrate. In fact, it is 71 percent carbohydrate, primarily made up of starch. On weight control diets, it is actually permitted as a bread exchange.
Popcorn is not only a good source of carbohydrates, but fiber as well. However, movie theater popcorn presents much more of a health concern than microwave or stove-top popcorn. In the quantities served at movie theaters, popcorn contains as many as 1,200 calories, principally from carbohydrates, as well as 580 milligrams of sodium. This is before movie theater "butter" is added into the mix. Compared to many nutritious snack foods, it is not an ideal option, due to its lack of protein and its high concentration of blood sugar-spiking carbohydrates.