Based on what I've read, I think the 90% fat combined with 1000 is the ket, more than the specific foods eaten. Dr. A based his recommendation on the Kekwick and Pawan study.
"“Calorie Intake in Relation to Body Weight Changes in the Obese,” Lancet, July 28, 1956, 155-161 by Alan Kekwick and Gaston Pawan.
Basically, what they did was to take a group of overweight subjects and put them in three groups. Each group received 1000 calories per day. One group was fed 90% carbohydrates, the second group 90% protein, and the third group 90% fat.
The group receiving 90% carbohydrates gained an average of 0,24 pounds per day of the study. The group receiving 90 protein lost an average of 0,6 pounds per day of the study, and the group receiving 90% fat lost an average of 0,9 pounds per day of the study.
This clearly demonstrates the superiority of diets high in protein and fats over diets high in carbohydrates. Note that each group received only 1000 calories per day. It’s interesting to note that even at the very restricted level of 1000 calories per day, subjects fed 90% carbohydrates actually GAINED weight."
http://www.paunchiness.com/kekwick-...t-loss-results/
I think the most fascinating part is the weight gain seen in high carb, very low calorie participants. I've never bought into the whole calories in/calories out theory. But then, I have insulin resistence, so I am living proof that calories isn't the whole story here.