I can relate - I have a full boar nut case bro who about 4 - 5 years ago started to hone in what he would eat and this of course spilled over into what he objected to my parents eating. While freaking out about seeds or any oils derived from them, he'll instead use thick slices of butter on whatever he eats. Not bread though :) Funny thing is he has supposedly has a pancreatic issue - oh how he argues with my father when he gets out old medical books that state eating excess fat like butter isn't good for his supposed condition. I say supposed because I don't trust anything that leaves his lips ... and he's always got something worse in about the same place when someone has had themselves a very nasty injury.