File talk:Land-use-of-different-diets-Poore-Nemecek.png

these data cannot be true

The main facts against this diagram are:

proteins from plants are completely different from those from animals, nutrition with plant proteins requires much more of them and a supplementation with vitamines
fish and chicken may be more effective in protein production than mutton and beef but they need more food protein which must be produced by agriculture.
beef and mutton are able to produce worthful proteines from grass incl. cellulose because they are ruminants, they have bacterial processes which are able to do this, This is not the case for humans, chicken, fish...