Alright, fine.
It might differ in cities but considering I'm more rural I do have to travel around to find fast food. Generally for me where I am, I have 2 options: Fish n chip shops are the staple for proper fast food. Serving basically everything deep fried as scotland is sure proud to serve deep fried pizza, mars bars, haggis and whatever else they can get their hands on. The second option would be bakeries - sausage rolls, pastry bakes, savoury pies are very popular lunch options. You know very healthy options, if I want healthy food I have to go to a grocery store and grab a sandwich.
So generally you can find good old classic fish n' chip shops in almost every place, mediocre Chinese and Indian restaurants and taste of America. Taste of America meaning McDonald's, burger king, five guys (milkshakes are to die for), kfc and other random places. That being said, the only fast food chain I seem to like in America is Steak n'shake which was everywhere in the southeast the last time I was over there. Places like McDonald's and burger king absolutely suck compared to the uk versions, better with regional branches for a decent burger.