When I'm sticking to my plan of no sugar, no grains, etc., 100%, I feel great, I look better, and weight comes off easy. When I get complacent and start allowing things to creep in (corn tortillas, etc.) and still remain about 90% good, I stall out and maintain. It sucks that its such a fine line, but at least know where the line is!
For your reading pleasure, how pasta not bacon makes you fat: