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.
Eternals (comics)
Due to the cosmic energy that suffuses an Eternal's body and the nigh-unbreakable mental hold they have over their physiological processes, the Eternals of Earth are effectively immortal. They live for millennia, do not fatigue from physical exertion, are immune to disease and poison, and are unaffected by environmental extremes of cold and heat. Most cannot be injured by conventional weaponry, and even if they somehow are, an Eternal can rapidly regenerate any damage as long as they are able to retain their mental hold over their bodies; this mental bond can be broken however. In the 2006 series it was also stated that Eternals are able to absorb oxygen directly from water, and therefore cannot drown. In the same series, Ikaris was plunged into molten metal and experienced great pain, but no physical injury, which the Deviants attributed to a forcefield which protects Ikaris even when unconscious. It is unclear if all Eternals share this degree of protection.