you'd be suprised at how long your villagers last without food, just yesterday i ran out of food and had 9000 tech points to go before i could reach farming lvl 3 and i only had 13 villagers, since they were weakend almost to detha they were extremely slow and i had to sit there for atleast 3 hours making sure my villagers stayed at the research table....i hope i never have to do that again, but i saved my village!