I don't know if anyone has sat down to calculate this. A lot depends on the speed setting. The faster the setting the more the villagers eat. To make up for that, the food has more value per item harvested, although the maximum available for honey is still 500 and 1000 for each fruit tree. That means that the food available will be used up faster on the faster settings. I don't know, but it is possible that the difficulty level might have some bearing, too.

Regeneration is also difficult to quantify. I think it occurs once an hour, but I'm not sure. It also depends on the faction chosen; Nature means that the food regenerates more than Magic. Certainly the hive only seems to regenerate a couple of points a time. The trees seems to regenerate around 200 a time (in Nature). Often, unless you are watching the villagers closely, they will start emptying the hive and the trees as soon as the food regenerates, even if you have fishing.