A Thousand Paths To Comfort

In the book, A Thousand Paths To Comfort, by David Baird, there is a quote from "Orson Welles", which I don't understand the implication of it:

My doctor told me to stop having intimate dinners for four. Unless there are three other people.

Well, when it is going to be a four-intimate dinner, it means that there must be four people! it's obvious. Then what does it mean when he say "unless there are three other people"? If there are not three other people it would not be a four-dinner!

He lays out enough food for an intimate dinner for four people -- and then eats it himself (because he's dining alone). It's like ordering the Chateaubriand for Two ... just for yourself. :)
    

The doctor was, quite amusingly, implying that Mr Welles was eating four times as much food as he should. He was eating an intimate dinner for four every time he ate alone. So he advised him to only have a meal for four when there were three others with him, and have a meal for one when alone.

Oh, now it's quite clear. Thanks a lot both :)

https://forum.wordreference.com/threads/an-intimate-dinner-for-four.2509520/