I don't know how anyone can eat most fast food--Taco Bell, McDonald's, KFC, Burger King etc--. Its greasy and has about an entire day's worth of calories.
Even their so-called "lite" menu items are not particularly healthy as far as fat content or calories.
Well it's fine as an occasional treat (depending on your definition of treat of course) or if you're in a hurry.
But if you've made it a way of life and are eating fast food daily, yeah it's bad for you.
I have a friend who has eaten at Taco Bell daily for almost 10 years now.
He ain't lookin' too good.