Originally Posted by spikyblackhair
Hehe, it reminds me of a blip I read in the L.A. Times saying that "when you wake up hungry, that means you've lost weight overnight"... ridiculous. There is too much misinformation floating around out there.
Waking up hungry has nothing to do with losing weight when one sleeps. People definitely lose weight during the night. I went on a diet a year and a half ago where I lost forty pounds in two months. Since then, I have weighed myself first thing in the morning when I get out of bed and last thing as night before I get under the covers. (Keeps me "on track".)
There is always a 2-4 pound difference between the two readings. I asked my physician son-in-law who works in sports medicine (he is the football physician at one of the smaller Florida universities) why this is so. Why do I lose weight when I'm sleeping seeing that I'm not doing any exercise? Two pounds is 7000 calories!
He said that the weight loss during sleeping hours is almost totally due to respiration. We are basically losing water, being expelled with every breath we take.
Same thing with tennis. After a match, a lot of our weight loss is due to water loss in our bodies, (by sweating, not respiration). That in addition to the 500-1000 calorie loss due to physical exertion.