I could have sworn I heard something once about how fast food chains put addictive chemicals in their food. For me, I don't have an addictive personality. There's nothing in my life I feel addicted to other than fast food. It's weird. I know the food is dogshit and I can make tastier stuff at home. But I also think about getting fast food all the time and have to stop myself from ordering it a lot. It does kind feel like a dopamine hit when I open up a bag of fast food and start digging in.
I was always told that Starbucks puts more caffeine in their drinks to get you addicted but looking it up now it doesn't seem to be the case. They're the target of a class action suit alleging they don't put enough caffeine as the drinks get larger.