I find that for me, when I eat particularly salty foods, that I retain alot of water even when its not the TOM. I'm talking about soy sauce for me sashimi or processed meats and poultry.

If you do a food journal here, then other can take a look at what exactly you are eating and try to give you feedback that way.

My question to you is... Do you write your food down anywhere? Can you look at the food you ate the day before you see these small gains? This is what I've done and I have learned that for me, its a salt issue. It may be the same for you or it may be something else.