That does seem frustrating
... But, I take it your bf is an adult, right? Then it's really up to him about what he eats... he doesn't have to eat something that seems like it may cause him problems later on. Instead, he could start making some of his own meals. It would probably be healthier and he'd have better success in controlling his blood sugar b/c it would make him more aware of what he's eating.
I know that may not seem like the easiest option, but I think if he has a problem with what his mother makes, he has to be the one to say something.
Good luck
