Like anything else, moderation is what makes it happen.
A McDonalds breakfast is a once every few weeks kind of thing. My usual is Cheerios and a banana, 1 percent milk, and no additional sugar. I'm no saint, but only an idiot would eat fast food every day, and all fast food places nowadays provide healthier choices. The salads are pretty good at McDonalds too, with some grilled chicken if you like.