As someone who likes junk food myself, particularly popcorn, I must realize that there are healthier ways for me to prepare and eat my favorite snack. For example, I use a hot air popcorn popper as shown below (cost ~$20). This avoids the extra calories from making popcorn in hot oil. Air popped popcorn is about 31 calories/cup (vs. oil popped corn being 47 calories/cup), and contains a significant amount of protein and fiber, in addition to carbohydrates. It also helps to not douse your popcorn with too much butter/margarine or salt.
Check out the following link for other helpful tips by Rachel Linder. In the article she describes “what happens to your body when you eat popcorn.”