> Growing plants to feed animals and then consuming those animals is an inefficient way of obtaining calories and nutrients. Shifting to a plant-based diet would allow us to feed more people with less land, reducing the pressure on wild habitats.
Regarding this point, it's important to remember that animals have the ability to transform materials we can't get any sustenance from, because they're not edible, into food. To get the idea, think how pigs have been historically such a popular food in many countries. They would basically eat anything, the owners get the pig fat, then they eat the pig.
Another thing to remember is that proteins coming from vegetables are low quality compared to their animal counterparts. For the great majority of the world population a vegan diet is inaccessible. You simply don't get all the nutrients you need from vegetables alone. Friends who maintain a vegan diet for ideological reasons have to supplement it with a heavy dose of pills and other compounds lest they have have problem maintaining their energy levels, even if they have calorie rich diets.
I'm aware. Not necessary in 21st century (in most of the world).
> proteins coming from vegetables are low quality
Protein "quality" relates to the presence of essential amino acids. Animal proteins contain all nine essential amino acids and are thus considered "complete."
Plant proteins often lack one or more essential amino acids. However, they aren't "low quality" - you just need to consume a variety of plant proteins (like legumes, nuts, seeds, whole grains) to get all the essential amino acids.
This process is called protein combining. As long as you're eating a varied diet throughout the day, your body can assemble the necessary amino acids. Plus, plant proteins provide other nutritional benefits like fiber and antioxidants (as opposed to inflamation-inducing effects of meat and dairy).
> Friends who maintain a vegan diet for ideological reasons have to supplement it with a heavy dose of pills ...
Also not true - only B12 is necessary. It's often a part of animal feed anyway, so why not skip the intermediary.
They are low quality precisely because they are less rich in types of amino acids. Given the option of having animal or vegetable-based proteins you would always pick animal, all other things being equal.
Having a “varied” diet is much easier said than done. Even people who are well off, living in rich and developed countries have difficulty maintaining this balance. This is a personal observation, but I suspect a lot of people underestimate how hard it is to maintain this lifestyle.
Another aspect that I don’t see discussed anywhere is that you need to have diversity of vegetables just to maintain a functional diet, what will happen to people when for some reason there are problems in the supply chain of a specific crop, you have a bad year with low yields and the price goes to the roof?
Another false assumption is that everyone can accommodate a purely plant-based diet.
But all other things will never be equal because animal protein costs 10x more energy to produce.
> what will happen to people when for reason there’s a problem in the supply chain of a specific crop or you have a bad year with low yields and the price goes to the roof?
Have you been to a produce department? Most of them in the US could be reduced to 25% their current size and still have 200% the diversity of the meat department. Being unable to find one or more amino acids is just not a problem that vegetarians have.
The problem is constantly having to cook for yourself because vegetarian options at most restaurants (or prepared by well-meaning carnivore friends) are just "leave the meat off" and not designed from the ground up to be nutritional without meat. Cultural change would make it easy.
> Having a “varied” diet is much easier said than done
I think you overestimate what varied means in this context, usually two or three different protein sources are enough.
Consider a random day where I tracked my food intake: I ate some oatmeal for breakfast and dinner, and noodles with chickpeas for for lunch. In the end I had between 120% to 250% of the RDA for the different essential amino acids.
Edit: Also "Another false assumption is that everyone can accommodate a purely plant-based diet". Do you have a source on that, with maybe an estimation to what percent of the population this applies to?
To your second point, we'll agree that a plant-based diet with supplements is feasible for human health.
Your first point is misleading because we currently grow a lot of food to feed animals to eat, and clear out forests to make pasture.
- "More than three-quarters (77%) of soy is used as feed for livestock."[1]
- "Seventy per cent of formerly forested land in the Amazon, and 91% of land deforested since 1970, is used for livestock pasture."[2]
- 38.7% of Corn produced in the US is for livestock feed.[3]
I fail to see the point of your thought experiment
In reality people are not isolated 10 acres plots of land, they eat what is available at the grocery store, which is part of an industry and a global chain of production. If you remove that, you should provide a valid reason. You're also welcome to go watch gamechangers to see what they have to say about nutrition, they have Phds I believe
I'm not carried away by credentials. There are some morons around with Phds. And I'm sure that you will find some Phds who will find fault with with what is espoused in gamechangers. My point is just because you look at a documentary, or even published papers, you as an individual cannot decide easily, because there are opposing views even among people with a lot of credentials. Of course most people choose to go with consensus. But then consensus itself can be quite wrong.
That's great - feel free to inform yourself about nutrition, Gamechangers is a good source of information about nutrition, using all kinds of evidence. I myself am healthy and have now been vegan for 8 or 9 years, eating a vast majority of cheap and local-ish food
(Edit: local ish in the sense that I eat banans and stuff like that like a normal human being)
The fact that they had to make a movie showing that people can have muscles following a plant-based diet proves my point. If it was widely feasible, they wouldn't have to create propaganda to support the point.
That's kinda circular isn't it? "Since they made a movie it has to be fake"?
Come on my friend, at least try. And without even thinking about my nutrition I am a healthy vegan since 9 years, not taking supplements and eating cheap localish food.
Regarding this point, it's important to remember that animals have the ability to transform materials we can't get any sustenance from, because they're not edible, into food. To get the idea, think how pigs have been historically such a popular food in many countries. They would basically eat anything, the owners get the pig fat, then they eat the pig.
Another thing to remember is that proteins coming from vegetables are low quality compared to their animal counterparts. For the great majority of the world population a vegan diet is inaccessible. You simply don't get all the nutrients you need from vegetables alone. Friends who maintain a vegan diet for ideological reasons have to supplement it with a heavy dose of pills and other compounds lest they have have problem maintaining their energy levels, even if they have calorie rich diets.