This is interesting that you are starting to introduce carbs. I have been feeling the same way lately. I started doing some research and came across some older threads with bobo and it doesn't seem that there are any metabolic advantages to a low carb approach. in fact most of the studies state that carbs and protein induce a greater thermic response and that carbs are more muscle sparing than fats.
I do believe that you can excrete water and glycogen when eliminating this macro nutrient but this only seems advantageous when wanting to look ultra ripped.(like right before a competition) Then there is the super compensation aspect of the AD but having done a 40-40-20 with AP for several months I feel that this is just as effective, for shuttling nutrients, as an AD style diet.
It appears that most of the studies that support little or no carbs are based on obese patients. It is my understanding that they metabolize food very different than a person with respectable bodyfat.
People seem to get all amped up (including myself) when they see that the have lost 10lbs after week or so and think that it is a miracle diet. In all reality when you do a certain eating style it all comes down to calories in vs calories out in the long run. (referring to your fat loss statement)
Are you currently bulking, cutting , maintaining?