> Are you suggesting that the reason the US/Europe is not at the Malthusian limit / has a low population growth is because we don't grow enough food?

Population growth isn't being restricted by food availability. As to the other questions, I wouldn't want to argue causation in either direction. I'm pretty sure it goes in both.

If we started to reproduce at the level supported by our food production, we'd end up in the Malthusian equilibrium.