Air-Popped Popcorn Calories: Understanding Nutritional Information

Question
Hi, Not too long ago you answered a couple of questions for me and thought I'd ask you another one.  I have found several places that tell me that there is 31 calories in one cup of air popped popcorn.  On the actual bag of popcorn it says there is 20 calories in one cup.  If a person ate a lot of popcorn the extra 11 calories per cup can add up.  Which one do I believe.  I like air popped popcorn for a healthy snack.  I use fat free cooking spray (butter flavored) and then lightly salt it.  Thank-you,  Tracy

Answer
Hi Tracy

There can be a slight difference based on the brand sometimes. What you do to be sure is add up all the macro nutrients. The protein carbs and fat.Their are 4 calories in each gram of protein and carbohydrate and 9 in each gram of fat. Add up what the food label claims and try to base it on that