sodium snack. Popcorn. In 1 cup of air popped popcorn there is 64 calories, 4.8 grams of fat, 116 mg of sodium, 5 grams of carbohydrate, and 0.8 grams of protein. You could drizzle the popcorn with 1 tsp of olive oil (monounsaturated fat) and crushed rosemary for a satisfying snack, adding 40 calories, 4 grams of fat to the snack.