Yeah, with more details it doesn’t sound like a huge deal. Not ideal, but not the end of the world. At that age, the two main problems with too much fast food are poor nutrition (which it sounds like you and the kid between you are already doing plenty to counter - five fast-food meals a week won’t leave him malnourished, if he makes up for them the rest of th etime) and obesity, which sounds like it isn’t a problem for him.
You could also suggest healthier forms of takeout. Japanese and Thai both tend to be pretty healthy, or at least to have plenty of healthy options on the menu. Get a bunch of menus and give them to him.