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.
Cryptobiosis
Anhydrobiosis is the most studied form of cryptobiosis and occurs in situations of extreme desiccation. The term "anhydrobiosis" derives from the Greek for "life without water" and is most commonly used for the desiccation tolerance observed in certain invertebrate animals such as bdelloid rotifers, tardigrades, brine shrimp, nematodes, and at least one insect, a species of chironomid ("Polypedilum vanderplanki"). However, other life forms, including the resurrection plant "Craterostigma plantagineum", the majority of plant seeds, and many microorganisms such as bakers' yeast, also exhibit desiccation tolerance. Studies have shown that some anhydrobiotic organisms can survive for decades, even centuries, in the dry state.