Humans are omnivores, and have been for the lifespan of our species
There are a number of important nutrients that humans get from animal products that are difficult to get from plant-based sources, including vitamin B12, which is not present in land-based plant species (I’m not sure whether red algae counts as a plant, so I’m playing it safe with land-based)
This is one argument @darganon. We need nutrients from a variety of things. We can live without some of them but that can come at the cost of health later in life e.g Vegetarian women more likely to fracture hips in later life.
Furthermore:
animal-source foods (ASFs) are dense in bioavailable vitamins and minerals. ASFs are the only intrinsic food source of vitamin B12 [7] and contain more bioavailable forms of vitamins A and D, iron, and zinc than plant source foods (PSFs)
Then there’s land-use:
• 86% of the global livestock feed intake in dry matter consists of feed materials that are not currently edible for humans
• Contrary to commonly cited figures, 1 kg of meat requires 2.8 kg of human-edible feed for ruminants and 3.2 for monogastrics
• Livestock consume one third of global cereal production and uses about 40% of global arable land
It wouldn’t surprise me if we evolved to have balanced diet from multiple sources because they have the nutrients we require. We most likely don’t need all the meat we’re eating and we do a terrible job in developed countries with reducing waste. But just like a purely meat based diet, a purely plant based diet is just one of the extremes. To each their own though.
That being said, a lot of people (myself included) eat far more animal products, particularly meat, than needed
There are a number of factors at play there, including government subsidies for feed crops and meat production artificially driving up its availability
