Diet

Diet is a concern for members of late-stage civilizations according to Oswald Spengler; that society has moved to a reflective stage. Not so for young cultures red in tooth and claw! Also young cultures are generally doing the growth thing, and have not yet reached "oops, look at what a mess we've made." And most everyone is a parasite, beyond those living directly off solar and various other metabolic paths.

Distance from the equator is a factor; more distant generally means that more meat in the diet. More distant also means a less supportive environment; elderly in the Arctic Circle were generally pushed out to die when they could no longer contribute, while in India one might go on walkabout and could still be fed enough to survive, usually. There can also be cultural norms here, provided the environment supports the excess.

Modern practice has upended a number of conventions, notably how far the food is transported, what sort of food is available and when, etc. With this comes various problems such as damage to the ecosphere and to social systems: aquifers can be overused, topsoil lost, large operations can undersell and ruin small outfits and then jack up the prices, etc.

Details are important; a vegan diet based on cane sugar involving dubious labor practices and vast corporate soylent holdings may be worse than a omnivore who eats from a local farm, especially where the local farm is doing an animal and crop rotation thing to better maintain the soil. Granted, there will be perhaps less meat and milk from this farm than a modern might have grown used to, nor eggs all the year round. Other problems include that the small farm may not be profitable enough, or that the small farm food may be too expensive. This can be a complicated problem to optimize.