6. Microwave Popcorn
Movie-theater popcorn may be bad for you because of the oils it’s popped in and the butter on top, but at least making it doesn’t cause “popcorn lung” — don’t laugh, that’s a real disease. It’s also known as bronchiolitis obliterans.
Butter-flavored microwave popcorn doesn’t really get its flavor from butter; it gets it from chemicals and flavoring agents. Diacetyl is what most people will point a finger at when they talk about how the health risks of microwave popcorn. Diacetyl is a butter-flavoring agent used in microwave popcorn — by the end of the 2000s, some manufacturers banned its use in popcorn bags because of its respiratory risks (and, separately, a link to Alzheimer’s disease), but you’ll also find it giving a buttery flavor and smell to baked goods, candy and margarine.