Sadly it's more than today's population. Take for instance Wickard v. Filburn (1942), a law was upheld that prevented farmers from growing food in order to prop up food prices. An Ohio farmer was forbidden to grow wheat to feed his own livestock, not even sell it.

> An Ohio farmer, Roscoe Filburn, was growing wheat to feed animals on his own farm. The US government had established limits on wheat production, based on the acreage owned by a farmer, to stabilize wheat prices and supplies. Filburn grew more than was permitted and so was ordered to pay a penalty. In response, he said that because his wheat was not sold, it could not be regulated as commerce, let alone "interstate" commerce (described in the Constitution as "Commerce... among the several states"). The Supreme Court disagreed: "Whether the subject of the regulation in question was 'production', 'consumption', or 'marketing' is, therefore, not material for purposes of deciding the question of federal power before us.... But even if appellee's activity be local and though it may not be regarded as commerce, it may still, whatever its nature, be reached by Congress if it exerts a substantial economic effect on interstate commerce and this irrespective of whether such effect is what might at some earlier time have been defined as 'direct' or 'indirect.'

[0] https://en.wikipedia.org/wiki/Wickard_v._Filburn