I think there are many studies on the overall health of hunter-gatherers as a result of diet and exercise and leisure time as demanded by the lifestyle. In early agricultural societies you have to work harder and longer and you're forced to eat a lot of bread, potatoes and corn and other low quality foods.
> H-G numbers were kept in check by available resources randomly dispersed in nature.
But... doesn't "numbers were kept in check" mean "surplus people starved to death"?
Not so obviously. Would you argue this for (say) lions or eagles? Few adults starve, when times are lean there is less breeding, and fewer kids who survive, compared to times of plenty.
Whereas the collapse of an early agricultural society (perhaps due to pests, or just no rain) probably did result in lots of adults starving, if there were more of them than could be supported on gathered food.
In the sense that the diets & health of ordinary people were much worse under early agriculture. This appears to have been true for a long time, maybe until a few centuries ago.
People ran away if they could. Early agricultural societies seem more and more like attempts by warlords to enslave both animals and humans for their benefit. Capturing livestock & farmers seems to have been the main goal of warfare.
> also an incredibly good deal, in that it now supports 7000 million human lives
Sure, 21st century life is (for almost all of us) much better. It's not so clear that 19th C life was so (except for a few highly-developed places).
http://www.zo.utexas.edu/courses/THOC/Readings/Diamond_Worst...
TL;DR: there are trade-offs.
edit: I forgot to mention, there may be a third way that combines the best of both worlds: "Redesigning Civilization with Permaculture" (video) http://tobyhemenway.com/videos/redesigning-civilization-with... sequel to "How Permaculture Can Save Humanity and the Planet – But Not Civilization" http://tobyhemenway.com/videos/how-permaculture-can-save-hum...
I keep hearing this, and it's probably true in some sense.
But agriculture is also an incredibly good deal, in that it now supports 7000 million human lives. H&G only reached about 50 million.
So it becomes a philosophical question: Is it better to have a few happy people alive or a huge population of less happy ones?
I'm reminded of the old "explorer's fallacy", where you encounter a tribe in the jungle and marvel at how healthy everyone is. Not realizing that the sick and infirm aren't allowed to live there.