Water In, Water Out

I've weighed myself a whole bunch of times today, and my weight is jumping all over the place. I'm 99% sure that isn't due to the scale I'm using, which means my weight is actually changing. It's got to be because of differences at different times of day between what goes in and what comes out.

I'm pretty sure most of it is water. As I understand it, the dietary guidelines say to consume 8 cups of water per day. I drink 15 to 25 cups per day.

(By the way, that's not as high as it sounds. For one thing, because I eat very little in a day, I'm not getting water from food. Many of the foods you eat in a day include a considerable amount of water. Lettuce and broccoli, for example, are more than 90% water. Carrots and apples are about 85% water. Some of the water goes to make up for that. Besides, unless you force yourself to drink way beyond your thirst, excess water won't hurt you.)

Each cup weighs about half a pound, so I drink 8 to 12 pounds of water per day.

So, all day long it's drink some liquid, go to the bathroom, drink some liquid, go to the bathroom...several pounds of water in, several pounds of water out. The amount I can drink before my bladder fills up depends in part on what else I've had to eat. Food in my stomach slows the absorption of water into my bloodstream, and salty foods cause me to retain water rather than eliminating it right away. On the other hand, my blood pressure medication causes me to eliminate water faster.

It's a roller coaster, and my weight goes up and down with it.