1. I didn't lose a whole bunch of weight on NROLFW. I think at the end of the experience I dropped a total of 12 lbs. But that said....
2. I didn't follow the "diet" part of it until the end of the program. I kinda had a laissez-faire attitude towards eats until around September of last year, when I began really buckling down on the food and realized that I was cheating myself out of the plan by not following its complete protocol. So when I finally got my act together, I tried complying with the recommended daily macros and calories as much as possible, and lo and behold, I started losing weight.
One caveat: I didn't really have that much to lose - the 12 lbs. lost was sufficient for me. However, I think you can achieve weight loss of 40 lbs.+ on the program, because the magic won't come from the exercises themselves, but from the nutrition front. Cassandra Forsythe provides two sets of formulas in the book, one for maintenance and the other for fat-loss, where you can figure out your daily nutrition needs and recommended calorie intake. I followed the latter, and it produced results.