Re: Does the Body loose weight at moment of death because of energy lose

Does the body lose weight at the moment of death?

I am aware of no rigorous study that has actually tried to address this 
question. So, the only correct answer that I can give you is: I don’t 
know. But, I can share some of my insights into human physiology to show 
you why I think the answer to your question is no.

First off, let’s straighten out the differences between kinetic and 
potential energy. Potential energy is stored energy – in the body it is 
stored mostly in the forms of food (in various stages of digestion) and 
fat. Other forms of potential energy exist within the human body, but by 
definition potential energy will remain just that – potential – once a 
person dies. Death would bring about no change in potential energy from 
the perspective of human physiology. Kinetic energy is the energy of 
movement. A dying, bedridden, person’s kinetic energy would be represented 
by the beating heart and the associated blood flow, the movement of the 
breathing muscles, and some functions of basal metabolism. Most of this 
energy is degraded as body heat. Once a person dies, no more body heat is 
created – and I suppose that would be the measurable kinetic energy loss 
associated with death.

How much kinetic energy is lost? In a normal, healthy person, daily 
activity requires about 2000 kilocalories of energy (it will vary 
depending upon sex, size, and a few other things). A dying person would 
almost certainly use less energy, but let’s keep the number 2000 
kilocalories for the sake of simplicity. That means that a person would 
expend about (create kinetic energy of about) 20 calories per second to 
stay alive (2000000 calories / 24 hours/60 minutes per hour / 60 seconds 
per minute.

So now we have 20 calories of kinetic energy at the second of death (I’m 
using the second of death since “moment” is not quantifiable, but would be 
a small number in any case). Now lets invoke the E=MC^2 equation. To 
calculate the amount of mass associated with this energy we need to solve 
for M, which is M= E/C^2. So, to calculate the mass, we need to divide 20 
calories by the speed of light squared. The speed of light is 3 x 10^8 
meters/sec, squared that comes to 9 x 10^16. Dividing 20 by 9x10^16 comes 
to about 2 x 10^-16. In other words, the amount mass lost each second (at 
the moment of death or otherwise) is about 0.0000000000000002 grams. I’m 
not sure that I’ve done all the unit conversions properly, but in any case 
the amount of mass lost is remarkably small. So small, in fact, that a 
greater amount of weight would be lost due to the air that is exhaled and 
the sweat that evaporates from the skin. For all practical purposes, this 
number is so small that most biologists would be unable to measure it. 
That’s as close to zero as you ever get in biology.