I can tell you that if I were to try it it is because the basic primal blueprint diet has gotten the inuslin-resistance weight off nicely but nothing more than that. I could easily lose 10-20 more pounds and almost look like the image of pretty in the success stories he normally posts. All the exercises have just left me wrecked and sore to the point of not being able to roll over in bed for 4 days per week. After 9 months of the exercises and sprinting and spending over half those 9 months being sore with no weight loss, I'm sick of all that. But I haven't tried this potato thing.
Female, 5'3", 50, Starting weight: 163lbs. Current weight: 135 (more or less).
I can squat 192.5lbs, press 75lbs and deadlift 210lbs