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.
Microcystin-LR
Cyanobacteria prefer to live in water bodies such as lake, ponds, reservoirs, and slow-moving streams. When the water is warm there are enough nutrients available for the bacteria to survive. Most cyanobacteria produce toxins, of which microcystin is only one group. When a cyanobacterium dies, its cell wall degrades while the toxins are released in the water. Microcystins are extremely stable in water and withstand chemical breakdown such as hydrolysis or oxidation. The half-life of this toxin is 3 weeks at pH 1 and 40 °C. At typical conditions in the environment, however, the half-life is 10 weeks.