Frankly, I left. (It wasn't just the breath - he also tried to run me over with a car, but that's another post for another day.) Anyway, my ex had terrible breath. We tried diet changes, more frequent dentist visits, tongue cleaning, etc. Nothing ever worked and his bad breath is one of the many reasons I'm glad to have left. But, since your friend's husband seems to be better after eating, that could point to dental hygiene as a solution. Have they talked to a doctor or dentist?