I was quoting Diana Rogers, who provided a source for her statements, so I thought I would include it.
I cannot access the full article, but from the abstract that seems to not be congruent with what the study is suggest. Perhaps you are confusing kg for kcal? It could indeed be the fact that it is 3x less efficient by weight.
Given that the article is pointing out that 86% of the feed for animals is not edible by humans, claiming that meat is 3x less efficient calorie wise with these numbers is also making the claim that we are growing plants 2x more calorically dense by meat than weight.
I cannot access the full article, but from the abstract that seems to not be congruent with what the study is suggest. Perhaps you are confusing kg for kcal? It could indeed be the fact that it is 3x less efficient by weight.
Given that the article is pointing out that 86% of the feed for animals is not edible by humans, claiming that meat is 3x less efficient calorie wise with these numbers is also making the claim that we are growing plants 2x more calorically dense by meat than weight.