It is controversial though. Vegans have higher rates of depression and anxiety than the general cheeseburger eating population which has terrible rates of depression and anxiety. They also have higher rates of auto-immune disorders. The major benefit of their diet comes from toxicity reduction from eating optimised daily calories.
A plant sits in one spot thinking how to poison anything that eats too much of it. An animal moves about consuming as little poison as possible.
Once you're assured of enough calories (which used to limit population growth) the primary solution is to eat some calories from animals that evolved systems for processing plant toxins to minimise your toxic load.
I used pea goo in the comment because I went to the beyond meat website and looked at the ingredients in the impossible burger. The impossible burger consists of about 15 chemical compounds, combined by people highly financially motivated to optimise flavour, texture and colour and the primary component is pea protein. If you can think of a more concise name I'm all ears but it's definitely not a iphone or macbook air.
Vegan's choose pea goo over lamb. That's their choice and some vegan's will have the genetic biochemistry to live healthily on a plant based diet. The general population doesn't share that biochemistry. Veganism is the most environmentally sound option if one's health optimises from the diet. Unfortunately this is not the case for the majority of the population. The average vegan should be admired for their sacrifice, not their logic.