You now have FOOD in your system instead of the liquid you've been living on for weeks!! Of course there'll be a little gain? Make sure you've plenty of fibre to help keep things 'moving' and you'll be fine at your weigh-in. Even if you're up a lb, don't despair- your system has to get re-used to digesting foods and processing them, so for some it may take a little longer, but as long as you keep up your water intake and stick to the guidelines, you should be fine? Look at Summergurls results for week 1- she's had rice and alcohol and lost 2.5lbs? Now I know not everyone will have the same results, but it should help keep you focused?