My guess is that at a certain point we will have to reconsider our animal based food habits, not based on ethics but on efficiency mainly. We gain some specific

My guess is that at a certain point we will have to reconsider our animal based food habits, not based on ethics but on efficiency mainly. We gain some specific contributions from them (B12 vitamin etc) but for others (most proteins included) there should be more efficient ways to get them. The higher you are on the food chain, the more efficiency you loose on the process, so it would better be for something specifically produced at that point of the chain.