I get credit for giving him the food, and on the next visit he is thankful and is now scavenging around, but it does not unlock any new lootable areas and he doesn't reference whatever he was talking about before. In my previous playthroughs I had never gave him anything so I don't know his intended behavior, but walking me down to the basement and then staying silent doesn't seem right.
I uploaded a video of the entire visit here:
http://youtu.be/Bvswo1Rtmb4
(giving him food is around 4:00)
Please let me know if I can provide anything else.