People often do lose weight faster, but you need to take into consideration their current weight. I am a RN and by no means an expert, but I took a lot of nutrition classes in nursing schools and recommended safe weight loss is 1% of your body weight a week. People that weigh more use more calories just to survive and a heavier person who stays on program is more likely to lose at a faster rate, at least initially. If you cut calories by too much, then you defeat yourself by cutting your metabolism as well. I know this didn't offer any advise on how to lose, but maybe it may explain some things?
"Make the most of yourself, for that is all there is of you" - Emerson