We have talked about previous set point plateaus,immunity to injectible HCG, water retention, TOM, impact of exercise, or food additives on weight loss.
I am wondering if part of what we are seeing is calories per day required to maintain weight dropping as we continue successfully losing:
http://www.caloriecontrol.org/healthy-weight-tool-kit/weight-maintenance-calculator-women
(this is an interesting calculator customized to your age and height as well)
If I put in my height of 5'6' and my current weight around 175 I come up with a daily caloric need of 2,187 with moderate exercise. Three weeks ago at my starting weight I needed 2,383 per day. At my goal weight of 145, I would need 2,056 calories a day.
So it seems that on top of all the other reasons we have mentioned, I would be burning a little less with each week that passes on the HCG. That may explain who people claim it takes them longer to the lose the last few when they are closer to their goal weight.