Overnight - I just don't understand!

Can anyone explain why it is that I go to bed on average 2 lbs heavier than when I weigh myself in the morning? (And why sometimes its 1.5 lbs, and sometimes 3??)

Hmmm...it must be those pesky sleep pixies coming at night and stealing your pounds! ; ) I've encountered the same thing, but I think it might be me sweating at night.

you are carrying the weight of the water and the food that you ate earlier in the day. That's why its best to weigh yourself in the morning then leave the scale alone....I'm trying to break being a slave to the scale myself. I did read about a neat trick though that says to either hide the scale someplace out of sight or tape your ideal weight over the readout. Because your weight can also fluctuate from day to day as well, dependent upon how much water you are carrying etc. It's hard for me not to measure my progress by the weight. It does help though that  I go to Curves and they take all of your measurements plus measure body fat, so you know whether or not you are making progress, regardless of the scale readout.

Over the course of the day you are consuming foods and beverages that add fluid to your body, especially if you are also eating salt.  When you sleep, your body uses up glycogen stores in your liver.  So in the morning, you have less water and lower glycogen stores.  Hence, lower weight.  That is why people who go on high protein diets often lose so much weight in the beginning.  No, it isn't fat, it is your glycogen stores!

I always weigh-in first thing in the morning specifically because I'm lightest then. At the end of the day , I'm usually a few pounds heavier than I was in the morning.

I always weigh in at the same time.  If I can't make it one day, I catch it the next.