For years I ate margarine. It started when I was a student and was trying to save money. It continued partly because margarine was meant to be better for you. It turns out this isn't necessarily the case.
David Friedman, in his post Salt, Official Truth and the New York Times, explains why this is the case. There is also a touching anecdote about his days at Harvard. It must have been odd to hear your father mocked by someone who had no idea who you were.