Is a vegetable that you cut and cook now dead and thus toxic? Is any type of meat from an animal that died and therefor it's toxic?
Freezing food does nothing to it's nutritional content except sometimes to stop chemical reactions from taking place inside the food, so it will stop the processes of converting some chemicals into nutrients, but all the nutrients that were in there before freezing are still in there.
Fast Food is about as kike as food gets, there's a reason it's the most non-kosher food in the world and they don't eat it. It's pure poison. Like that movie Supersize Me, I'm sure if someone remade that movie now the results would be even deadlier, they are only making that poison worse and worse.
Not totally sure what you're asking, but Fast Food is not any sort of substitution for healthy food that has been frozen. Just buy the ingredients and cook it yourself, that way it's healthier and tastes much better because you make it yourself how you think is perfect. Less money usually too, at first it seems like more money, but when you buy all the ingredients you have enough for multiple meals, so it ends up being cheaper once you have everything.