Human
In general, humans can survive for two to eight weeks without food, depending on stored body fat. Survival without water is usually limited to three or four days. About 36 million humans die every year from causes directly or indirectly related to starvation. Childhood malnutrition is also common and contributes to the global burden of disease. However global food distribution is not even, and obesity among some human populations has increased rapidly, leading to health complications and increased mortality in some developed, and a few developing countries. Worldwide over one billion people are obese, while in the United States 35% of people are obese, leading to this being described as an "obesity epidemic." Obesity is caused by consuming more calories than are expended, so excessive weight gain is usually caused by an energy-dense diet.
Inedia
Inedia (Latin for "fasting") or breatharianism is the belief that it is possible for a person to live without consuming food. Breatharians claim that food, and in some cases water, are not necessary for survival, and that humans can be sustained solely by "prana", the vital life force in Hinduism. According to Ayurveda, sunlight is one of the main sources of "prana", and some practitioners believe that it is possible for a person to survive on sunlight alone. The terms "breatharianism" or "inedia" may also refer to this philosophy when it is practiced as a lifestyle in place of the usual diet.