found this delightfully weird cereal commercial. Apparently in the 1960s there was a Post cereal called Size 8, trying to appeal to weight-conscious women.
Of course, today, size 8 is considered gargantuan in Hollywood -- it would have to be dubbed Size Double Zero.
But the best thing about it is not the odd name, but that it was sold not in a traditional cereal box, but in a mod paisley swirl patterened round cylinder. No, really.