Why is it called fast food? Because it can be prepared fast and you can buy it fast and you can eat it fast. But because it is too fast, it is not so healthy as those foods we have in normal way.
So, I think we can have the fast food when we are in a hurry or just when we want something else for change.
So, i think fast food should never be the main food for us.
And as a matter of fact, I love chinese food best. As it is both delicious and healthy.