This diet from 1970 was simple. Just eat only pineapple for two days every week. On the other days you can eat whatever you want. The book is apparently quite a rarity, because I haven't been able to find any used copies for sale.
Over at vice.com
, a guy recently tried the diet and claims that he lost 1 kilogram (2.2 lbs) in three days. Which, actually, isn't a lot. Evidently, he was able to find a copy of the book. He also discovered that one of its authors, Sten Hegeler, was still alive, 93 years old. When contacted, Hegeler admitted that not a lot of deep thought went into the concept of the diet:
"Pineapple with whipped cream was the preferred dessert back then, so I thought, 'My god, I can have as much pineapple as I want for two days,' and that sounded splendid."
And a bonus for linguaphiles: The word "erogetic" appears to have been invented for this book. I'm not sure what it means.
Fort Myers News-Press - Sep 16, 1970
Chicago Tribune - Nov 5, 1970