For almost ten thousand years the human diet was largely based on what was cultivated and harvested, supplemented by very small amounts of animal (including fish) protein. How was this a factor in the relatively slow growth of the human population before the industrial revolution.

For almost ten thousand years the human diet was largely based on what was cultivated and harvested, supplemented by very small amounts of animal (including fish) protein.  How was this a factor in the relatively slow growth of the human population before the industrial revolution.