> beneath us on the food chain

This sounds... tautological. We can morally eat whatever we can eat? Does that include gorilla meat? Weaker humans?

The OP provides no justification, so in his mind, yes. And when AI develops, or a new race of genetically engineered humans, they can eat us, too. But I'm sure the OP wasn't thinking about being boiled alive when he made his comment.

>humans are entitled to a certain degree of leeway in this regard. Sustainably eating the plants and animals beneath us on the food chain is one of those areas.

If we ever come into contact with extraterrestrial life, I hope that they don't share this view.

I hope they do, because we are going to eat them.

> Animal protein is an essential component of nourishing billions of people

It doesn't have to be; in fact, humans, animals, and the planet would be much better off in many ways were we to transition to plant-based diets:

Go vegan, save the planet https://www.cnn.com/2017/04/08/opinions/go-vegan-save-the-pl...

Five things would happen if everyone stopped eating meat http://www.independent.co.uk/voices/five-things-would-happen...

What would happen if everyone went vegan? https://www.bbcgoodfood.com/howto/guide/what-would-world-loo...

What the Health http://www.whatthehealthfilm.com

The Game Changers http://gamechangersmovie.com

Cowspiracy http://www.cowspiracy.com

If the extensively[1] debunked[2] "What the Health" makes your list, I'm skeptical of the standards to which you hold your sources.

Can you provide peer reviewed papers making claims comparable to the sources you provided?

[1] https://www.vox.com/platform/amp/science-and-health/2017/7/2...

[2] http://time.com/4897133/vegan-netflix-what-the-health/

Thanks for the heads up on "What the Health". Sadly, I can no longer edit the submission.

For a meticulously documented presentation, see "How Not To Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers" https://www.youtube.com/watch?v=lXXXygDRyBU

I‘m not convinced that killing plants is creating less suffering than killing simple animals like shrimps or insects for example. Listen to the latest radiolab episode for example. Given their capabilities I find it reasonable to assume that the level of consciousness is about the same (which includes the very likely possibility of them being not conscious at all).

Point is, if you want to just reduce suffering while staying healthy (e.g. no iron / B12 deficiency) there may be better answers than just to restrict oneself to the one half of living creatures that happens to generate its own food from CO2.

I think you got the setup of that radio lab episode and not the later points. The points was that: a) plants are a lot cooler than you think b) looking at things from a non-standard position can lead to new insights even if that position might be wrong c) anthropomorphizing causes people to assign values to them that may or may not exist regardless of other evidence.

The turn was after hooking you on all of the feelings by anthropomorphizing the plants more to you, then went back to cold logical examination that there is no structure in the plant for pain or learning and literally pointed out the manipulation they did. Radiolab does this a lot, manipulates the listener to get you meta insight into yourself.

I think that in a century people will look back and consider us barbarians for eating meat whilst they chow down on their lab grown "ham"-burgers.

We surely can't be that far off of this now?

The Vegetarian Myth https://www.amazon.com/dp/B003PJ7JXY/

But lobsters are so much tastier than tofu. :-(

There are people who have averse reactions to almost every plant based food, and can largely only eat meat or suffer horrible mental and physical health problems.

Diet is not one-size-fits all, and we have basically no idea how complex diet is, or the specific long term effects of most dietary interventions on people. It is absolutely reprehensible to represent going vegan as an obvious way forward when it is unclear that it's even safe for a large majority of people.

Can you link to a description of that condition? It sounds fascinating.

Seems to be unstudied, but this person[0] reports has both severe mental and physical reactions currently to almost anything other than meat, though she was able to eat some vegetables safely before. Her father has similar reactions to many plant-based foods, and they both have had serious disorders activated seemingly by diet, especially severe depression.

In addition, many people are unable to eat yeast or yeast extracts, which are among the few commonly available non-flesh sources of the crucial vitamin B12.

[0]: http://mikhailapeterson.com/2017/12/18/zero-carb-carnivore-d...