Ella Pickover, Press Association June 19, 2012
Food security threat... being overweight could exacerbate a lack of ecological sustainability due to increasing population sizes.
LONDON: Overweight people are a threat to future food security and increasing population fatness could have the same implications for world food demands as an extra billion people, researchers have found.
Scientists from the London School of Hygiene and Tropical Medicine examined the average weight of adults across the globe and said tackling population weight was crucial for food security and ecological sustainability.
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 world's adult population weighs 287 million tonnes, 15 million tonnes of which is due to being overweight and 3.5 million tonnes to obesity, according to the study, which is to be published in BMC Public Health.
The data, collected from the UN and the World Health Organisation, shows that while the average global weight per person is 62 kilograms in 2005, Britons weighed 75 kilograms. In the US, the average adult weighed 81 kilograms. Across Europe, the average was 70.8 kilograms compared with just 57.7 kilograms in Asia.
More than half of people living in Europe are overweight compared with only 24.2 per cent of Asian people. Almost three-quarters of people living in North America are overweight.
Researchers predict that if all people had the same average body mass index as Americans, the total human biomass would increase by 58 million tonnes.
The authors of the study say the energy requirement of humans depends not only on numbers but average mass.
''Increasing biomass will have important implications for global resource requirements, including food demand and the overall ecological footprint of our species,'' they wrote.
''Although the concept of biomass is rarely applied to the human species, the ecological implications of increasing body mass are significant and ought to be taken into account when evaluating future trends and planning for future resource challenges. Tackling population fatness may be critical to world food security and ecological sustainability.''
Professor Ian Roberts, who led the research at LSHTM, said: ''Everyone accepts that population growth threatens global environmental sustainability - our study shows that population fatness is also a major threat.''