Being honest with yourself is the KEY in losing weight and that is what I have found..There is no point going like 'oh I'll do it the next time' or 'its just for this one time'.
NO!!!
Stop lying and believe me that's the hardest part. So I have developed this method every time you feel like relapsing or lying to yourself, take an apple and start munching on it and then think of your goal..Its working for me but I'm no miracle case it takes loads of will power.
I realised that you should always have a goal, a dress you want to fit in(something like that) don't always rely on the scales because it may not come down quick enough but you might fit in that sooner than the pounds drop in a big way. It just makes it a slightly bit easier.
Its not so easy but these little things makes it a bit more bearable.
Good luck to me and those out there too*hehe*