Subject: Re: Question: 10% energy absorption from food
From: [email-masked] (Alec Edgington)
Date: 11 Aug 1994 13:01:14 GMT
Newsgroups: sci.med.nutrition,bionet.plants

In article <[email-masked]> [email-masked] writes:
>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...
>
>
There is something wrong with this argument. The fact is that no
ecosystem can exist in isolation. The plant world needs the animal
world, for carbon dioxide, continuance of the nutrient cycle through
animals' excreta, etc etc. You cannot simply take animals away or your
"orchard" will suffer and die. So really by taking away the pigs you
throw out the baby with the bathwater. And somebody or something will
have to eat those pigs and carry on the cycles. Nothing, no fly or
joule, is wasted in nature.