It is often thought that the life of the hunter-gatherer was one of feast and famine. But most available data suggest that they were surprisingly healthy and had a fairly stable diet and lifestyle. Not so the primitive farmers. In years when the crops failed, in settlements where the population density was high and where disease weakened the ability to cope even further, life would have been very hard indeed. The settled population could not migrate to follow the food supply as could hunter-gatherers. They were trapped.
Peter Gluckman, Mismatch: Why Our World No Longer Fits Our Bodies
anthropology, biology