I'm intrigued by this potato diet and keep an open mind about it. A few days is not a fad where there's a basis of scientific reasoning. Individual success is of course very context dependent - the metabolism/thyroid stimulating effects for someone who had previously been chronically eating a very low carb diet are obvious.
The arguments I've seen here that Grok never had the luxury of micromanaging his macronutrient intake or eating a 'balanced diet' within the timescale of a few days are very valid IMO.
F 5 ft 3. HW: 196 lbs. Primal SW (May 2011): 182 lbs (42% BF)... W June '12: 160 lbs (29% BF) (UK size 12, US size 8). GW: ~24% BF - have ditched the scales til I fit into a pair of UK size 10 bootcut jeans. Currently aligning towards 'The Perfect Health Diet' having swapped some fat for potatoes.