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.
Bactrian camel
Bactrian camels are exceptionally adept at withstanding wide variations in temperature, ranging from freezing cold to blistering heat. They have a remarkable ability to go without water for months at a time, but when water is available they may drink up to 57 liters at once. When well fed, the humps are plump and erect, but as resources decline, the humps shrink and lean to the side. When moving faster than a walking speed, they pace, by stepping forwards with both legs on the same side (as opposed to trotting, using alternate diagonals as done by most other quadrupeds). Speeds of up to have been recorded, but they rarely move this fast. Bactrian camels are also said to be good swimmers. The sense of sight is well developed and the sense of smell is extremely good. The lifespan of Bactrian camels is estimated at up to 50 years, often 20 to 40 in captivity.