Ideally, I suppose. But maybe they boil them like my Gran used to boil veg - until there's barely any nutrition left in them. And then add artificial colours and preservatives and whatnot. It's like if you make bread at home, then it's reasonably healthy, but it's difficult to buy bread that isn't essentially junk food, because they'll do anything to make the rise process quicker (including throwing in a bunch of sugar).