I was going to question what you said sakura_girl, but having thought about it I agree with you.
When someone is in a significant calorie deficit, water loss is coupled with fat loss via glycogen depletion regardless of the macronutrient content of the diet.
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.