Popcorn used in dieting?

While looking thru some on-line books on popcorn, I ran across a guy who had written a few on using popcorn while dieting. If memory serves me right most of his books were printed during the 1970’s. I know popcorn is low in fat if popped correctly or if you use a hot air popcorn popper. It takes almost the amount of calories to chew up popcorn as it contains too. But if you add a heavy coating of a candied glaze such as caramel corn or make popcorn balls or use a recipe high in sugar it defeats the purpose of using popcorn in a diet. If you want a low fat snack you can use a hot air popcorn popper. Spritz the popcorn with a spray butter substitute and lightly salt it. I used my hot air popper to make popcorn that was free of oils so I could use it in my homemade caramel corn. I made a special stainless steel pan with four inch high sides so I could double the batch or add extras to the popcorn like peanuts, pecans etc…