For awhile LL drank an incredible amount of coffee. So much that they initially made his draft rating 4F. He had a slightly enlarged heart from training to be a fighter and the Army Dr. thought he had some serious sort of problem

That worried him and he went to a real Dr. who told him to cut back.

That incident appears in his fiction in Flint ... Flint is diagnosed with cancer when he really just has ulcers.

In my youth the coffee was just at breakfast and after meals though there was plenty of it, but then he cut back and went to decaf in the late 1970s.