I have no choice but to weigh in after work. COD opens at 9, I'm at work at 5, obviously I've eaten breakfast and a snack by 9 am.
Otherwise I try not to eat 90 minutes before weigh in, but weigh in at the same time every week. Years ago when I was on WW, the leader came right out and said that as long as you're weighing in at a consistent time with consistent circumstances the scale will be consistent. That's how I look at it. I alwasy weigh in about 2 hours after lunch on a Tuesday, thus the scale will be consistent from week to week.