Hi my dad was diagnosed t2 in he's early 60s did exactly the same thing.....bloody shame because he really enjoyed life and would have been a happy 80 yr old but due to him behaving like your dad he died at 67 from a heart attack never knowing he had a heart problem, there's a mountain of advice you could give him, but the hard thing is making him listen or want to change he's ways, it makes me so sad reading your post, I pray to god you can help him, there's no reason he couldn't live on and on if he can be convinced, diet is vital but not an easy route for anyone who likes eating sweet (bad) food like him and me for that matter, maybe get him to come to this site himself as we'll as you and read some horror stories about the possible complications he could get, I don't know the answers but I wished I'd done exactly what you have before it was too late, very very best of luck to you both, look up some low carb eating threads, it's a place to start