I know a lot of people at my group tend to think that anything they eat after weigh-in somehow escapes in "no-man's land", and are invisible to everyone, even the scales .... lol .... some get away with it and others definitely don't! ...... I personally haven't tried it! lol
I used to get really annoyed if I stayed the same or put weight ON at weigh-in .... that's when I would kinda "pig out" and go home via the chippie, kebab shop for chinese! I'd get right back to basics next day though, and USUALLY I'd get away with that ..... somehow!
What I DO tend to do though, is to give myself a "treat" when I lose .... I treat myself to a new lippy, or eyeliner, or if I've got a bit of extra cash, maybe a new top or go for a tan stand, or go to the hairdressers, get a manicure, something just for me! .... much nicer treats! Definitely SYN FREE!!!!!