Subject: Re: Question: 10% energy absorption from food
From: [email-masked] (Renate A Wesselingh)
Date: 8 Aug 1994 06:00:21 GMT
Newsgroups: sci.med.nutrition,bionet.plants

In article <[email-masked]>, [email-masked] (David Eng)
 writes:
>my original question was about the energy pyramid.
>
>actually, I've got a question about this 10% figure now.  Does that mean,
>if I ate a piece of apple pie at 100 calories, I would only be utilizing
>about 10 of these calories, the rest being sent down the toilet?  The
>recommendation of 2600 calories a day, does that mean we really only need
>260 calories, the other 90% or, 2340 calories being wasted by our bodies?
>
>dave

This 10% does not mean that the other 90% is wasted, but is used for other
purposes than biomass production, such as thermoregulation and locomotion.
It roughly means that if you want the caloric equivalent of one apple from
pork, you will have to feed the pig 10 apples. Then it has set on the extra
weight that is equivalent of this one apple. This argument is often used in
favour of vegetarianism. One orchard could sustain (let's say) 10 pigs, and
those would suffice for one human, whereas that same orchard can feed 10
persons if they eat apples instead of pork. I simplified it a bit, but this
is the basic idea. 2600 calories are recommended because at that level you
will not put on weight: it means that all calories are used to keep you
alive. Extra calories would be converted into fat. As you see, the more you
eat, the more efficient the process of biomass production gets...

-----
Renate A. Wesselingh ..................................................|
Institute of Evolutionary and Ecological Sciences .....................|
Leiden University, PO Box 9516, 2300 RA Leiden, The Netherlands .......|
[email-masked] ...........................................|