Re:
This is not the actual maths in play, and there are more variables to account for i know, but this is tge basic principle at work...
Imagine a 1 acre field is grown for maize or wheat or such like, and the total calorific content of that food resource is 1000calories. A herbivore eating 100% of that food resource will convert around 10% of the calories into useful, life sustaining processes such as heating, motion, cell production, breathing and energy etc... so 100calories
Now imagine a carnivore (or omnivore) eats the herbivore. Again, around 10% of the energy or calories of the herbivore are converted by the carnivore
Basically, each step up the foodchain wastes a huge amount of energy, which is essentially why i became a vegetarian in my early 20's
Now imagine locally produced and sourced, wild boar and chilli sausages, on an open fire while smashed one night with my mates (one if whom is on here... you know who you are!), and that is why i started eating meat again after nearly 15 years
G