Firstly, if he was in KCH he would have been in good care.
I am surprised that he wasn't given any advice on further lifestyle.
He must now live a normal life for him...and this will be modified by pain in his legs when walking (intermittent claudication)......gardening, golf and anything that he feels that he would like to do.
Diet?...well there are plenty of opinions on diet, but I would suggest that he eats whatever he feels like, in moderation.
Any other specific questions, then do get back to us.