# Lose weight by breathe

A doctor or assistant can measure with a spirometer,
the lungs absorb an average of 0·3 liters of oxygen
every minute if the patient is at rest.

This oxygen is used to burn the fuel in the blood, glucose.
A number of intermediate steps happen and excipients are used.
The end result is that carbon dioxide and water vapor are exhaled.

1·0 mole of gas or vapour has a volume of about 22 liter depending on temperature.
Then 0·3 liter oxygen is an amount of (0·3 / 22) mole = 14 mmole.

The net chemical reaction is C6H12O6 + 6O2 → 6CO2 + 6H2O.
For each mole:
180 gram glucose + 192 gram oxygen → 264 gram carbon dioxide + 108 gram water vapor.
It is about 372 grams both before and after the reaction.
So the conservation law of mass is satisfied.

A ratio table or proportion table:
 duration volumeoxygen amount ofoxygen mass ofoxygen amount ofglucose mass ofglucose 7·4 hours 134 6 192 1 180 1·0 minute 0·3 0·013 0·43 0·0022 0·4 24 hours 432 19 619 3·2 580 liter mole gram mole gram
Conclusion
Solely and exclusively by breathing at rest, everyone loses 580 grams of glucose.
So everybode loses 0·6 kg of weight by not eating.

Chemistry