but I've only lost 1lb

I think that the recommended portions are too large....usually I cut calories to around 1200, but this plan has them up around 1500. Does anyone modify the plan and make it lower cal? Does it work for you that way?
I know part of it may be because I've been working out so much (cardio 6 days a week plus muscle toning/strength training on three on those days---I can even see ab definition. I have a one pack! haha) ...but i also read on these forums that even gaining a pound of muscle takes a lot of work, so it's doubtful that i could have gained more than a lb or two just in June.
Anyway, what do you guys think? should i try the plan next week eating every three hours, but cut the potions back? (maybe 3-300cal meals and 2-100cal snacks)