So what if it can achieve rapid weight loss? Anyone can achieve that by extreme restriction of calories and being bloody minded enough, without having to follow x,y,z diet plan to the letter.
Low fat causes cannabilisation of essential fatty acids from the brain and internal organs unless very carefully formulated essential fatty acid supplements are taken. I'm not just talking fish oil here. I've not seen anyone get healthy on a low fat diet - quite the opposite in fact. I've seen friends destroy their health to the point where they've been unable to work for years. It's tragic.
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.