If the guy's lost 50lbs then he must be doing something right. Many here would sell their firstborn to do just that.
Nothing wrong with 'enlightening' people, but you have to let them come round in their own time. When you keep banning on the paleo drum you sound like a religious zealot.
Religious dude: Brother, you'll be so much happier if you let (insert deity) into your heart!
Dude: I'm already happy.
Religious dude: No, no you don't know real happiness , please let me come in and talk to you, it will only take a minute!
Dude: Erm..I gotta go, I've like got something in the oven.
Religious dude: Please just give me a chance to explain, you don't know what you're missing!
Dude: I gotta go man..
Religious dude: Bu..bu..
*sound of pamphlets being pushed through mail slot*..