Question: how many calories in one cup of hot air popcorn?
Answer: Air-popped popcorn contains only 31 calories per cup. A cup of popcorn also contains 1.2 grams of fiber and less than 1 gram of fat. While popcorn contains only small amounts of vitamins and minerals, such as magnesium, potassium, and vitamin A, it has high levels of antioxidants.