what to eat day before weigh in??

Avoid high sodium. They make you retain water and you'll probably appear as if you lost nothing or gained weight. Drink lots of water too.

I think the best thing to do is to eat like you eat every day. And if the scale doesn't show any progress this week, it will happen next week. I understand that you want to see a lower number on the scale, but I think that by adapting what you eat to when you're having a weigh-in gets you so focused and alert on the scale that you only get extra disappointed and demotivated when you don't meet your expectations. And don't get me wrong, its a learning process, it took me a lot of time to start thinking this way. But I've seen myself gradually losing 2 pounds per week. And then all of a sudden I would stay on thesame weight for one week and then losing 3, 4 or even 5 pounds the next week. I guess what I'm trying to tell you that you should be proud of yourself according to your nutrition even if the scale may sometimes say otherwise..