While the protein extracts from fungi or from plants solve the problem of the non-animal sources of protein having an undesirable ratio between protein content and energy content, they are much more expensive than meat or eggs and they have an unknown environmental impact, due to high consumption of energy and of chemicals.
The fact that these protein extracts are more expensive than meat, per protein content, should be a strong clue that their real environmental impact is also worse, even if their producers avoid to document it.
I am aware of only a single method of protein extraction that can provide separated protein that is cheaper than chicken meat and which requires no chemicals that could leave residues in the protein and which uses little energy (but it requires an additional non-negligible water consumption). This is the extraction of gluten from wheat flour, by making a dough and washing it.
For the (relatively few) people who have gluten intolerance, this unique method is not applicable, but in many parts of the world (i.e. where soy is expensive) it is the only way that I know of that can be used for achieving a vegan diet that is less expensive than eating meat. Without gluten, a lower protein cost than for meat could be achieved only by combining vegetable protein sources like lentils with chicken eggs.
It's worse than animal agriculture based on what evidence?
Once you look at production at scale, these products dominate animal ag environmentally:
> a study published in Nature 2022 found that replacing 20 percent of per-capita ruminant meat, such as beef, with fermentation derived microbial protein, such as mycoprotein, could cut global deforestation and carbon dioxide emissions by 50% in addition to lowering methane emissions.
Also,
> it is the only way that I know of that can be used for achieving a vegan diet that is less expensive than eating meat.
I don't understand this. Even ChatGPT can come up with a solution to your question if you care to figure out how to eat a sufficient vegan diet without soy/gluten.
e.g. Legumes are cheaper than meat. For the sake of looking at real numbers, 1000 calories of cooked lentils has 80g protein (all of the EAAs) and 67% of the day's nutrients. Also, you'd have to substantiate why optimizing for protein is the only thing you seem to care about given that (1) you can reach the high end 1.6g/kg protein with this food and (2) there are dozens of other nutrients that matter.
But searching for these hypothetical cases where someone can't eat neither soy nor gluten just so you can finally launder in a chicken egg and go "A-ha!" seems to be a red herring that doesn't track anything in this conversation. Okay, now let's pretend they are allergic to chicken eggs, too. Ho hum.
A typical value would be to eat at least 1700 kcal of lentils to provide enough methionine (you need 543 g/day of lentils to provide enough methionine for an 170 lb human).
Even eating only 1000 kcal of lentils would not be considered pleasurable by most people, for whom such a quantity would be too much.
When you choose a diet, ensuring that you will enjoy that food is as important as not exceeding the kcal threshold and as exceeding the nutrient threshold.
Legumes are cheaper than meat (but not by much, chicken meat is only about 50% more expensive than legumes, per protein content), but you cannot eat only legumes and they cannot be the only important source of protein, you need at least a second source.
I care for protein because this is the main difficulty when you do not want to eat meat. Anything else can be easily obtained from vegetable sources or from supplements. I am annoyed when I see people who write vegan propaganda, while at the same time attempting to minimize the protein problem. I have been trying for years to become vegan, but without success, because I could not solve the protein problem, and almost all the vegan advice that I have seen has been completely useless, because it looked like it was written by people who did not care whether they pay $5 or $50 for a meal, or whether they waste 5 minutes for cooking or they waste an hour. Eventually I have solved the problem, but only after personal experiments and I would have liked very much to have wasted much less time with this.
I have no problem with gluten, so for myself gluten is a major source of protein. Nevertheless, if I had gluten intolerance, where I live, in Europe, the only alternative for achieving a 2000 kcal daily energy intake without meat and dairy (and without eating a diet that no free human would accept, like eating only lentils, water and a capsule of vitamins and minerals) would be chicken eggs (as a supplement for legumes).
At least here, protein extracts are typically 5 times more expensive than chicken meat (per protein content), so using them as a staple food would seem stupid.
You have not provided any alternative to what I have said and I bet that ChatGPT would give an answer that is either wrong or irrelevant.
> It's worse than animal agriculture based on what evidence?
Currently there is no evidence of any kind. The costs of meat production are well known, but the costs in energy and chemicals for the production of various kinds of protein extracts are not known, because they are "proprietary".
I nobody is able to offer for sale low-cost protein extracts for human consumption we can only assume that the production costs are high, i.e. that each pound of protein extract requires a large amount of energy and/or chemicals.
> a study published in Nature 2022 found that
Searching the Internet right now, I have found a non-paywalled copy of that study: "Projected environmental benefits of replacing beef with microbial protein".
Nevertheless, exactly like I have expected, that study is useless. It does not contain what the abstract says.
It contains what seems to be an accurate analysis of what would be gained if the production of meat would be reduced, by using an alternative source of protein.
Nevertheless, to compute the net benefit, we also need a computation of the production costs for the protein provided by the alternative source. Such a computation is missing from the article. There is no information about the energy consumption and about the chemicals consumption that would be required by the alternative sources.
Some forms of microbial fermentation can provide high-quality protein, perhaps even without any harmful substances that must be removed, but the protein has a low concentration in the growth medium. Separating the protein from the water and from the waste products of the fermentation would need much energy.
In the more distant future, growing a bioengineered multicellular organism, like a fungus or a parasitic plant, seems a much more viable path, because such an organism can grow a big edible fruiting body, with whatever nutritional composition and texture is desired. Such an edible fruiting body can be detached and used for cooking with minimal processing, without additional energy consumption.
The fact that these protein extracts are more expensive than meat, per protein content, should be a strong clue that their real environmental impact is also worse, even if their producers avoid to document it.
I am aware of only a single method of protein extraction that can provide separated protein that is cheaper than chicken meat and which requires no chemicals that could leave residues in the protein and which uses little energy (but it requires an additional non-negligible water consumption). This is the extraction of gluten from wheat flour, by making a dough and washing it.
For the (relatively few) people who have gluten intolerance, this unique method is not applicable, but in many parts of the world (i.e. where soy is expensive) it is the only way that I know of that can be used for achieving a vegan diet that is less expensive than eating meat. Without gluten, a lower protein cost than for meat could be achieved only by combining vegetable protein sources like lentils with chicken eggs.