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At night you still sweat and breathe. In fact weight loss in general occurs by breathing. Your body gets energy by breaking carbon bonds, then disposes of the

At night you still sweat and breathe. In fact weight loss in general occurs by breathing. Your body gets energy by breaking carbon bonds, then disposes of the carbon via breathing out CO2.

whamlastxmas 3y ago
There is zero way your body is losing a quarter pound at night through either process in a room at 70 degrees
- Cthulhu_ 3y ago
  A quarter pound is only just over 100 grams, or about two shot glasses; you'll just breathe that out as water vapor, and then some. Plus sweating happens even when you're not feeling moist.
- mecsred 3y ago
  According to [0], humans exhale about 11.0L of CO2 per hour at night. 02 in, CO2 out, so we can get mols of gas with ideal gas law and mass loss with molecular weight of carbon. If I did my math right, it comes out to 53.9g over 8 hours of sleep (if you can get that much ). (Americans: 0.118 lb/night). Not quite a quarter pound but maybe closer than you thought! [0]https://onlinelibrary.wiley.com/doi/10.1111/ina.12911 https://onlinelibrary.wiley.com/doi/10.1111/ina.12911
  - jjoonathan 3y ago
    Also, a Quarter Pounder is 417 Calories which is a bit less than 2000*8/24, so that checks out.
  - meragrin_ 3y ago
    We also lose H20 through exhalation. I imagine that can make up the difference.
    - mecsred 3y ago
      For sure, I would expect it to be more than the carbon difference. I think it would depend a lot more on circumstance so I couldn't really put concrete numbers to it here.
  - s1artibartfast 3y ago
    Another way to look at this is the human body stores energy in glucose and fat Fat is 77% carbon by weight, and glucose is 40% carbon by weight (C18H34O2, C₆H₁₂O₆) . All off that carbon is broken down to CO2 and removed by the blood and lungs. 2000 calories of fat is 0.57 lbs, and 0.44lbs of carbon. 2000 calories of glucose is 1.14 lbs, and 0.46lbs of carbon. The carbon masses are similar because the energy we use comes from breaking the carbon-carbon bonds these molecules. This means you exhale about a 0.45 lbs of carbon per day for baseline metabolism. Each pound of fat you lose is another 0.77 lbs of carbon on top of this (over however long you lost it). Compairing to your numbers, the approach above means you exhale 200g of carbon a day, and 8.3g/hr. If you sleep for 7 hours, that is 58 grams of carbon exhaled (pretty close).
- NullPrefix 3y ago
  Veritasium did a video on this. He lost around 250g each night, which is over half a pound. Some of that lost weight was CO2, some of it was water vapor and some of it was sweat. https://www.youtube.com/watch?v=lL2e0rWvjKI https://www.youtube.com/watch?v=lL2e0rWvjKI
  - deleted 3y ago
    [deleted]
  - whamlastxmas 3y ago
    Thanks for info - happy to accept I was wrong :)
- deleted 3y ago
  [deleted]

At night you still sweat and breathe. In fact weight loss in general occurs by breathing. Your body gets energy by breaking carbon bonds, then disposes of the carbon via breathing out CO2.

whamlastxmas 3y ago

There is zero way your body is losing a quarter pound at night through either process in a room at 70 degrees

Cthulhu_ 3y ago
A quarter pound is only just over 100 grams, or about two shot glasses; you'll just breathe that out as water vapor, and then some. Plus sweating happens even when you're not feeling moist.
mecsred 3y ago
According to [0], humans exhale about 11.0L of CO2 per hour at night. 02 in, CO2 out, so we can get mols of gas with ideal gas law and mass loss with molecular weight of carbon. If I did my math right, it comes out to 53.9g over 8 hours of sleep (if you can get that much ). (Americans: 0.118 lb/night). Not quite a quarter pound but maybe closer than you thought! [0]https://onlinelibrary.wiley.com/doi/10.1111/ina.12911 https://onlinelibrary.wiley.com/doi/10.1111/ina.12911
- jjoonathan 3y ago
  Also, a Quarter Pounder is 417 Calories which is a bit less than 2000*8/24, so that checks out.
- meragrin_ 3y ago
  We also lose H20 through exhalation. I imagine that can make up the difference.
  - mecsred 3y ago
    For sure, I would expect it to be more than the carbon difference. I think it would depend a lot more on circumstance so I couldn't really put concrete numbers to it here.
- s1artibartfast 3y ago
  Another way to look at this is the human body stores energy in glucose and fat Fat is 77% carbon by weight, and glucose is 40% carbon by weight (C18H34O2, C₆H₁₂O₆) . All off that carbon is broken down to CO2 and removed by the blood and lungs. 2000 calories of fat is 0.57 lbs, and 0.44lbs of carbon. 2000 calories of glucose is 1.14 lbs, and 0.46lbs of carbon. The carbon masses are similar because the energy we use comes from breaking the carbon-carbon bonds these molecules. This means you exhale about a 0.45 lbs of carbon per day for baseline metabolism. Each pound of fat you lose is another 0.77 lbs of carbon on top of this (over however long you lost it). Compairing to your numbers, the approach above means you exhale 200g of carbon a day, and 8.3g/hr. If you sleep for 7 hours, that is 58 grams of carbon exhaled (pretty close).
NullPrefix 3y ago
Veritasium did a video on this. He lost around 250g each night, which is over half a pound. Some of that lost weight was CO2, some of it was water vapor and some of it was sweat. https://www.youtube.com/watch?v=lL2e0rWvjKI https://www.youtube.com/watch?v=lL2e0rWvjKI
- deleted 3y ago
  [deleted]
- whamlastxmas 3y ago
  Thanks for info - happy to accept I was wrong :)
deleted 3y ago
[deleted]