There's a hint of truth in there. Farming increased the productivity of the land such that it could support more people. Some of the new people supported by t

There's a hint of truth in there. Farming increased the productivity of the land such that it could support more people. Some of the new people supported by the land weren't working it, such as bureaucrats and nobles. I'm don't know if the total calories per man hour went up or down, but the distribution of those man hours definitely became less uniform. Some people worked less, while most people probably worked more.