Population density in terms of human biomass in stead of numbers of people...

Last June Walpole and colleagues published a paper in BMC Public Health in which they looked at population density in a bit different way. They provided an overview of 'human biomass'  per region, i.e. the product of population size and average body mass. Their calculations and analyses show that in 2005, global adult human biomass was approximately 287 million tonnes, of which 15 million tonnes were due to overweight. Furthermore, and not surprising, the population size based on biomass is different from the number of people. One tonne of human biomass corresponds to approximately 12 adults in North America and 17 adults in Asia, and North America has 6% of the world population but 34% of biomass due to obesity while Asia has 61% of the world population but 13% of biomass due to obesity (please see the Figure that was copied from their open access paper). Their conclusion is that increasing population fatness could have the same implications for world food energy demands as an extra half a billion people living on the earth.