I'm sure most medieval people survived (without food types being a detriment to their health/lifespan) on vastly less meat than most of us eat nowadays.
I don't want to live a "medieval peasant" lifestyle, obviously, but I don't think the food part of it would be unhealthy (assuming enough food).
We’d be healthier, and the reduction of water use from all of the crops grown for feed would eliminate all water shortages in the west
Btw- the average male and female height adjusted for location keeps increasing which points to protein deficit: https://ourworldindata.org/human-height
(In the world graph towards the end the height seems to decrease since 1990s-this is because countries with shorter people have a higher birth rate. Within the same population the height is still increasing)
Average North Korean is now about 3 inches shorter than the average South Korean [0]. 70 years ago they were the same people with the same height... Both nations have very little in the way of immigration so this difference is all due to the environment (i.e. in this case nutrition).