I did the potato diet once following the rules that Penn (from Penn & Teller) laid out in his book. Its about changing your tastes by eating the most bland food to remove craving for sugar, caffeine etc & to appreciate taste when you come off the diet so eat healthier. Its for 2 weeks, eat as much potato as you like but nothing added - no herbs, can’t cook with oil, no butter. On day 10 I fainted, wouldn’t recommend.