Bah. It looks like an eariler, much more detailed and funnier reply got eaten by something.

But to answer, no, I don't think specifically and narrowly his butter eating lead to his rather large size, but rather his eating of almost everything that would taste good, and in quantities that were sometimes moderately impressive.

Given how much he ate and smoked, and how little he moved it's a wonder he wasn't twice as big and that he lived as long as he did.