1. I send along links to interesting articles/studies if they appear in publications that he respects. Additionally I have a friend who can discuss this stuff with me with equal fervor right in front of him, making him seem like he's the one who's not as knowledgeable. Both of these things I do very rarely.
2. I cook delicious meals that are both low or moderate in fat but highly decadent, such as perfect steaks or simple meals that are light and healthy with steamed veggies. Nothing I make ever swims in bacon fat. I like to declare that this is mediterranean food from <insert some mediterranean region here>.
The one worry I have is that his clinging to so much bread and processed food with all his complaints about joint pain, brain fog, poop and sleep problems and whatever else, that I'm going to end up with some Alzheimer's riddled old man who shuffles around and needs his butt wiped. I am not up for that, I'm sorry. But I've made a small dent. I haven't seen the pound of M&Ms eaten in a while. I haven't seen the huge bags of Doritos in a long time. He doesn't get mad at me as much when I send a link to something.