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.
International Water Management Institute
Although it was becoming evident that water could no longer be considered an "infinite resource", as had been the case in the 1950s when there were fewer people on the planet, no one knew just how scarce the resource was. This prompted IWMI to try to find out. Its research culminated in publication of "Water for food, Water for life: A comprehensive assessment of water management in agriculture". A map within the report showed that a third of the world’s population already suffered from ‘water scarcity’. The report defined physical water scarcity, as being where there are insufficient water resources to meet the demands of the population, and economic water scarcity as where water requirements are not satisfied because of a lack of investment in water or human capacity.
IWMI’s approach towards defining water scarcity provided a new context within which the scientific debate on water availability subsequently became centred. For example, the theme of the UN World Water Day in 2007 was Coping with Water Scarcity; The USA's Worldwatch Institute featured a chapter on water management in its assessment "State of the World 2008"; and reports published in 2009 by the World Economic Forum and UNESCO concluded that water scarcity is now a bigger threat than the global financial crisis. Dr. Rajendra K. Pachauri, Chair of the Intergovernmental Panel on Climate Change, also highlighted water scarcity at the 2009 Nobel Conference.