Hunger
Hunger is applied literally to the need or craving for food; it can also be applied metaphorically to cravings of other sorts.
The term is commonly used more broadly to refer to cases of widespread malnourishment or deprivation among populations, usually due to poverty or adverse agricultural conditions; see famine.
The term hungry also simply means ready for a meal.
Fasting is the practice of voluntarily not eating for a short period of time.