A large serving of movie popcorn is high in calories and loaded with fat, especially saturated fat. It's not just the buttery topping that is pumped onto the popcorn, it's also the oils the popcorn is fried in, such as coconut or canola oil, that add calories. Ingredients, calories and serving sizes vary by movie chain.
According to the Center for Science in the Public Interest, a large 20-cup bag of popcorn at a Regal theater contains 1,200 calories and 60 grams of saturated fat. At an AMC theater, a 16-cup large bag has 1,030 calories and 57 grams of saturated fat. At a Cinemark theater, a 17-cup large bag has 910 calories and 4 grams of saturated fat. Both Regal and AMC use coconut oil, which is 90 percent saturated fat, while Cinemark uses non-hydrogenated canola oil. The public interest group sent samples from major theater chains to an independent lab for testing. The popcorn results were published in the December 2009 issue of "Nutrition Action Health Letter."
These calories don't include any extra buttery topping. Two pumps of buttery topping will add at least another 240 calories and 4 grams of saturated fat to a large bag. When the Center for Science in the Public Interest had movie popcorn independently tested, the actual serving sizes were often larger than publicized, meaning you get even more calories for your money.
The purchase of a large bag of popcorn may come with free refills so there may be no limit to the numbers of calories you can consume while watching a movie. The saturated fat grams in a large bag of popcorn far exceed the 15 grams per day recommended by the Mayo Clinic.