Those arguments always drive me nuts because they're all so bro sciencey, and I'm not even vegan or vegetarian. Sure, meat offers a different set of nutritional value than vegetables - you can most definitely replace it entirely with other sources and remain very healthy. Billions of people have done it for centuries and continue to do so, as you've said.
A counter argument - billions of people subsisted on ok food for centuries, but somehow in the 20th and 21st centuries people got taller, smarter and had earlier puberties because of better nutrition.
Doesn't that mean there is a quality (and quantity) to nutrition and not just subsisting, that we need to examine? And the claim about meat is that it has a quality that is beneficial.
Certainly you have to look at causations for that holistically. People have cooked and eaten meat in the past as well. It needs to be further studied on the qualities that has driven our growth in the industrial age. I think we now have a better understanding of our bodies and how to gamify our growth, through a myriad of ways whether or not eating certain amounts of meat and balancing it with other foods.
Looking it up now I'm surprised to find that the only country with more than 15% of it's population being vegetarian is India. So now I'm somewhat skeptical of this claim. Will definitely need to do more research, but do you have any sources off hand? To be clear I'm looking to vet the claim that a vegetarian diet leads to similar health outcomes compared to a non-vegetarian diet.
There's really no way to answer those outcomes broadly because, for the vast majority of human beings, we don't count our calories or compute the macronutrients in our food. It's very difficult to see this unless you perform the study on twins, since birth, maintaining distinctly separate, perfectly controlled diets. The most consistent take is looking at it from an anthropological perspective - plenty of societies throughout history fed on a vegetarian lifestyle, which continues to persist today.
It would be interesting to see the stats of a country like India though, where you don't have confounders like vegetarianism often being a class signal like in the developed world. Although the more I look into it, the more I find that "vegetarian" is a pretty loose label there.
What societies in the past have mainly been vegetarian? None except India seem to persist to this day. I hear the human race took a pretty big hit in the early agricultural era as far as life expectancy goes.
>Health outcomes associated with vegetarian diets: An umbrella review of systematic reviews and meta-analyses
>Conclusions: Vegetarian diets are associated with beneficial effects on the blood lipid profile and a reduced risk of negative health outcomes, including diabetes, ischemic heart disease, and cancer risk. Among vegetarians, SDA vegetarians could represent a subgroup with a further reduced risk of negative health outcomes. Vegetarian diets have adverse outcomes on one-carbon metabolism. The effect of vegetarian diets among pregnant and lactating women requires specific attention. Well-designed prospective studies are warranted to evaluate the consequences of the prevalence of vitamin B12 deficiency during pregnancy and infancy on later life and of trace element deficits on cancer risks.
It's not brosciency, it's called bioavailablity. Ex: Carrots have a lot of a vitamin A precursor in the form of beta carotene, but the rate it's absorbed compared to the form commonly in the liver (retinol), is significantly lower and is reduced even further if you have certain health problems, including common ones like diabetes or insulin resistance.
