"Implementation of daily fasting decreases Villager hitpoints but increases all gather rates."—In-game description
Fasting is a technology in Age of Empires III: The Asian Dynasties that can be researched at a Trading Post built on a Sufi Mosque settlement. Once researched, it reduces the hit points of all villagers (including Fishing Boats) by 40% but allows Settlers, Coureurs des Bois, Settler Wagons, and Villagers to gather 10% faster (but not Fishing Boats, which only receive the penalty).
Note that with Fasting, villagers are quickly killed if attacked, making them more vulnerable and should be kept safe.