when I did this and lost great I was working out 5 times a week once I lost my first 30lbs. Before that my doc said no heavy impact stuff cause he was worried about knee damage.
After I started the treadmill everyday and upper body one day and lower body weights the next my weight loss seemed to cut in half. At that point I hired a personal trainer. She explained to me that muscle weighs much much more than fat. And that with my intense workouts I was adding more muscle than the weight of the fat lost. At that time she started taking measurments and man they were fallling fast. I went from a 56 to a 52 inch waist in a matter of 2 months. From a 5x shirt to a 3 x shirt in the same amount of time. And I still weighed 350 at the time!! I had 6 straight weeks with no scale loss. Then a lb. 2 or 3 more weeks no scale loss the 3 lbs.
I cant wait to get to 350 again so I can hit that treadmill.