you have a fascinating discussion going on in here! I often wonder whether we could convince even the staunchest low-fat/low-calorie dieter to switch to low-carb if we could force him to sit through a lecture in paleoanthropology. I'm a classicist but I've worked on archaeological excavations and dealt with paleolithic and mesolithic materials as well as neolithic (agricultural) and there is so much evidence that the worst disaster ever to befall the human race was Agriculture. I'm sure you know about this, but for anyone else reading this, I've had some thoughts about these subjects:

The reason population increased after the advent of agriculture is due to one single reason: a dramatic increase in the need for labor. As far as the statistics about how often hunter/gatherer women and agricultural women give birth go, they do not explain the reason for it. The reason is that hunters/gatherers rely on mobility, flexibility, and cohesion to procure food and protect themselves. Too many young children at once is dangerous. They self-regulate their populations. There is a great excess of leisure time in hunter/gatherer populations, and they do not need an extra workforce. With the advent of agriculture, leisure time disappeared. Children have always provided a secure and free workforce for the family, and it was at this time that children began to be reared as farm helpers. Population grew even though disease increased, sanitation was nonexistent (hunters/gatherers had excellent sanitation practices: they left when it got dirty), and the increasing desire for material acquisition caused internal strife.

One theory (I don't agree with this but I think it's really interesting) is that the reason people decided to raise crops is for alcohol. Grain, rice, potatoes, and corn all make alcohol. There is actually some archaeological evidence for this.

there is significant archaeological evidence from caves (a good example is Franchthi Cave in the Argolid in Greece) where paleolithic and mesolithic peoples spent a good part of each year for centuries, eating small game and a great deal of fish, as well as some lentils and other vegetables. All the Low-calorie advocates say we don't know what paleolithic and mesolithic people ate. As an archaeologist, I take that personally we do in fact know a great deal, and it is reliable--not only WHAT they ate, but HOW MUCH (relative proportions) of what they ate, and we can identify plant species, animal species, etc. Those low-calorie people say we only have evidence from teeth marks on bones! Oh PLEASE!! My area of expertise is Greece and the Mediterranean, but since many of us are ultimately of European extraction, this actually applies to many of us.

Of course the reason that our life expectancy is long now is that we artificially prolong it with antibiotics, antiviral drugs, anti this and anti that. We don't live healthier lives, even if they may be longer. We live lives supported by constant health care and ultimately die of one of our self-inflicted diseases. I wish I could be more articulate in this post, but it's very late at night so I can't, but I really would like to help people understand that if ALL OF HUMAN HISTORY WERE CONSIDERED TO HAVE LASTED FOR ONE YEAR, AGRICULTURE WOULD HAVE BEEN INTRODUCED ON DECEMBER 15. That means that we simply haven't evolved to be able to handle it yet!

I hope people find this interesting, there's more of course

Best, Kypraia