Concur with whoever said diet docs have, at best, a loose grasp of what the fuck they're talking about.
Additional evidence can be found
here.* I don't personally recall if Weight Watchers existed back in 1974, and cannot say with confidence whether these recipe cards are merely spoofs. If legit, however, may I just say
blechhh. How did people eat that crap?
* Spree -- Weight Watchers recipe cards from 1974. Nothing truly gross, except in the culinary sense.