What proportion of body weight is faeces?

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What proportion of body weight is faeces?
« on: 23/03/2011 08:23:23 »
@Sammybingo asked the Naked Scientists:
I want to know how much err.. bowel substance you need to have before you weigh more?

What do you think?
« Last Edit: 23/03/2011 08:23:23 by _system »


Offline chris

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What proportion of body weight is faeces?
« Reply #1 on: 23/03/2011 08:49:38 »
Delightful question, but one that's also often asked by dieters eager to shed a few extra ounces.

The average person defaecates daily, and the average stool mass is about 300g (higher in non-industrialised countries, lower in more developed countries).

Studies have shown that the transit time, i.e. the delay when food turns into faeces, is about 12 hours.

So, on this basis, there will be times when you have almost no faeces inside you (post a session on the loo and pre your next meal - hopefully the two won't synchronise...), there will be a time when you have 300g of faeces inside (post meal, pre-poop) and there will be other times when there are over 600g of faeces inside (post two meals and pre-poop).

I went hunting for a good quality reference to support my answer, hoping to find something in the "Anals of internal medicine" or an equivalently wittily-titled journal, but could only manage the Archives of Iranian Medicine; still, their data is helpful:



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