Ngl, just had a kid and I spend less on food because we don’t go out as often. It’s more of a hassle. And when we do go out we don’t get drinks or at least one of us doesn’t because we can’t take cabs with a baby.
Even with the multiple kid argument, there are economies of scale. You could almost make an argument that it’s more justifiable to eat out when you are single since most recipes seem scoped for a family and you might waste more food if you aren’t diligent about leftovers