Just a little insight from My perspective too...
I have been battling my weight since puberty.. And I have come to find that no matter what WOE you do... you will ALWAYS have weeks where you dont lose weight.
I know too that I have what my doctor has called a "Set-Point". THis is a spot where I sat at a constant range for a year or longer with out gaining or losing. I have one at 190 pounds... I have another (Where I am at right now) at 160-170. I was in this range for 10 years. It is a point where my body is comfortable and I have to work hard to break. I dont remember the last time I was below 160.. probably in Grammar School!!
The other thing to note is that when you start an exercise program... you may find that you stall out for a couple of week. The first reason for this is any muscle sorness you may have is caused by fluid retention in the muscles. Sounds weird, but once my doctor explained it to me it made sense. THe water is retained as a "soothing" element to the muscle. THe other reason is that although you are losing fat... you are gaining muscle when you exercise.. especially if you are doing any sort of resistance training. Muscle weighs more than fat! When I started atkins.. I started exercise in my 2nd month. For 2 weeks I didnt lose an ounce.. then the WHOOSH Fairy appeared and I lost 10 pounds in 2 weeks!
And remember.. the more muscle you gain.. the faster the fat loss!
Hope that helps some of you!