I weigh on average four to five pounds more at bedtime compared to when I wake up. Since I consume water or tea all day and evening I know I am floating when I go to bed, so I wake up two or three times per night to go to the bathroom. However, when I go to the bathroom I also go to the refrigerator and get a drink of water. I know quite well I am not losing five pounds of water in a night.
Where does that five pounds go? Do we evaporate at night?
Well, you do lose some water to sweating. (But if you are sweating 4-5 pounds a night, you would be waking up soaked. If you are, see a doctor!)
Also, in the course of 24 hours, the average person can urinate up to 2 liters, or over 4 pounds. If you are drinking a very large amount of water, you might in fact be losing that much every night.
Just how much water are you drinking in the average day?
There is no telling how much liquid I consume in a day. I literally NEVER have an empty glass. Each day I consume one full pitcher or more of decaff tea, a lot of diet beverage, some skim milk, and a lot of water. The glass never goes empty from starting with iced tea at sunrise to water at bedtime. I don't drink coffee at all---tastes like what I would think licking the bottom of an ashtray would taste like.
However, I know I'm not urinating four or five pounds during the night. And when I do go to the bathroom I go get a small drink of water.
It just baffles me that there is really and truly a four or five pound difference every single day between bedtime and getting up.