The author, Charles Redman, addresses pre-historic community nutrition as an aspect of early community forces. He observes that - surprisingly to many people - there's a great deal of mixed and negative evidence regarding the benefit to human being when agriculture and sedentary living enter the scene.
Overall, the various studies suggest a decline in the quality of life and possibly even a shortened life expectancy associated with the adoption of agriculture, despite a decline in the physical demands placed on the body (Cohen and Armelagos 1984). This conclusion requires us to reevaluate several generally held propositions about the advantages of agriculture over hunting and gathering. The simplistic notion of unimpeded human progress is ill founded. There was not a progressive increase in life expectancy; the picture was actually more complicated, with individuals in many hunting and gathering groups outliving those in agricultural groups. We have also found that hunter-gatherer groups were often better buffered against episodic food stress and sometimes had a more balanced diet than their farming counterparts. Nevertheless, since the advent of farming, regional and global population has grown dramatically. Moreover, much of this growth has included the repeated adoption of farming by former gathering people to the point where societies that rely on gathering are virtually extinct. This global population growth was accomplished in spite of a general dimunition of both child and adult life expectancies, a questionable advance in human diet, and a quantum increase in contagious diseases. This suggests that the forces, social and otherwise, that encouraged the adoption of agricuture and eventually of urbanism were extremely powerful, being able to override the negative impacts of early farming on those who attempted it. (Charles L. Redman, Human Impact on Ancient Environments (Tucson: The University of Arizona Press, 1999), 179.)
In a nutshell: Keep on eating berries, leaves, bugs, and critters you can catch either by yourself or with friends waving sharp sticks.