Here's looking at us: Most of the world's body fat is in U.S.

 Most of the world's fat is concentrated in one place. They're looking at us, America.

A study this month from the London School of Hygiene and Tropical Medicine reveals just how much the 7 billion of us on planet Earth weigh -- and that North Americans more than pull their own weight.

The study, published in the journal BMC Public Health, took into account those who were overweight, defined as a body mass index of at least 25, and obese, with a body mass index of 30 or higher.

287 million metric tons: Total weight of the world's adults, based on data from the United Nations and the World Health Organization. (A metric ton equals about 2,200 pounds.)

15 million metric tons: The weight of overweight adults

3.5 million metric tons: The weight of obese adults

62 kilograms (137 pounds): Average body mass worldwide

80.7 kilograms (178 pounds): Average body mass of North Americans, who make up just 6 percent of the world's population but 34 percent of the world's weight due to obesity. In contrast, Asia has 61 percent of the world's population but only 13 percent of its weight due to obesity.

Time to renew that gym membership?