The world's population is in danger of running out of food if the growing obesity problem is not tackled, scientists warned in a study published Monday.
The increasingly overweight population could have the same impact on food demands as an extra half billion people, researchers claimed after examining the average weight of adults across the globe.
The authors of the study, scientists from the London School of Hygiene and Tropical Medicine, said that the energy requirement of humans depends not only on numbers, but on average mass.
STUDY: Increasing population fatness could have the same implications for world food energy demands as an extra half a billion people living on the earth.
Tackling population weight is crucial for food security and ecological sustainability, they suggested.
"Everyone accepts that population growth threatens global environmental sustainability -- our study shows that population fatness is also a major threat," according to Prof. Ian Roberts, who led the research. "Unless we tackle both population and fatness, our chances are slim."
The world's adult population weighs 316 million tons, 16.5 million tons of which is due to being overweight and 3.9 million tons is due to obesity, according to the study published in the journal BMC Public Health.
The data, collected from the United Nations and the World Health Organization, shows that while the average global weight per person was 137 pounds in 2005, Britons weighed 165 pounds and the average adult in the US weighed in at 179 pounds.
Across Europe, the average weight was 156 pounds, compared with 127 pounds in Asia.
More than half of people living in Europe are overweight, compared with only 24.2 percent of Asian people. Almost three-quarters of people living in North America are overweight.
The United Nations predicts that by 2050, there could be a further 2.3 billion people on the planet and that the ecological implications of the rising population numbers will be exacerbated by increases in average body mass, the researchers added.