At some point, overpopulation will no longer be based on the size of the population, but rather the size of its waistline. North Americans represent just 6% of the world’s population, yet, account for 34% of the world’s human body mass, according to the London School of Hygiene and Tropical Medicine. That’s equivalent to 2.7 million fully loaded semis. On the other hand, China represents 61% of the world population, but only 13% of the global human biomass (1 million semis). There is the concern for health, but as nutrition improves in developing countries, the global food supply will start feeling some pressure. Researchers claim that if the 6.8 billion people on the planet had the same weight distribution as the U.S., and that number was divided by the average weight of a human being, the result would be 935 million extra people.