Hunger is a feeling experienced by animals when the glycogen level of the liver falls below a certain point. The usually unpleasant feeling originates in the hypothalamus and is released through receptors in the liver and stomach. An average nourished human can survive about 50 days without food intake, but only three days without liquids. Hunger can also be applied metaphorically to cravings of other sorts.
hunger is not the biggest crisis facing the world global warming is