I use up my time ploughing the landscape and making roads, I made a timber house as I hermit and thought it might not look to bad to make a few roads around the local area, I assume though from the exhaustion and my table full of various foods I have on it (particularly from the daily ant hill raids) is how you're supposed to be stat farming, though mining would probably work as well.
I don't have access to high tier foods, but there is a hella big patch of giant pumpkins nearby that's pumping my str and con up over time.