I stopped eating packaged popcorn back when the butter flavoring still contained large amounts of diacetyl. (supposedly they use less)
You can make your own microwave popcorn using a paper bag, and some olive oil.
1. mix 1/4 cup of popcorn kernels with a drop of olive/coconut/veg oil
2. put in paper bag and roll up the top tightly
3. push popcorn button on microwave (or wtvr)
4. add salt/butter, garlic butter/Italian seasoning/parmesean, nutritional yeast, etc...