In the 10% rule of energy in food pyramids, where does the other 90% go? I understand that only 10% of energy goes to the next trophic level, but where does the rest go?

1 Answer
Jan 7, 2016

The other 90% is "spent" performing other functions.

Explanation:

How much do you eat in a day? 3 pounds of food? 5 pounds of food?
How much weight do you gain in a day? certainly not 5 pounds! So where does all that food energy go?
Everything you do requires energy - walking, thinking, generating body heat, and so on. So of the food you eat, only a fraction goes in to making more "you", and the rest is used for everything else.
That "everything else" is referred to as metabolism , a word you have probably heard before, and in terms of the energy loss between trophic levels, we refer to it as "metabolic loss".