Here's my response from the Weight Loss section, more apt for this section:
[quote:2ef192a849="whiteknight"]It would seem to me that if I eat less than 2000 cal a day, and my usage is 4000, I would lose more weight.[/quote:2ef192a849]
WK, listen to the Cat: "[T]he Zone is not really based on calorie consumption, it is based on the control of hormones, like insulin."
You're making the mistake of thinking in terms of the traditional paradigm for exercise and weight loss: "Calories in, calories out." The laws of thermodynamics apply to a machine, but not to the highly complex systems that make up the human body.
It's about controlling insulin: If your pancreas isn't fooled into thinking it's famine season, your body will release its surplus energy, regardless of the work your muscles do.
To answer your question, Yes, it's possible for a very heavy person to lose 5 pounds or more per week once he begins controlling his insulin. A lot of that weight is stored water, and the rapid weight loss will slow down to a plateau of from one to one and a half pounds a week.
Enjoy the fast transformation while it lasts.