Hi, you might try chopping up some cooked spaghetti squash and substitute it for the usual cracker or bread crumbs used to mix with the ground meat. I think it would work. Shredded zucchini with some of the moisture pressed out might also work. Can your husband eat pearled barley? Maybe you could add some cooked barley to the meatloaf mixture.

I am really impressed with your husband's weight loss. Best wishes to him for his continued success.