Do Obese People Aggravate Global Warming?

"There is enough stigma attached to obesity as it is," said Dr. David Katz, director of the Yale Prevention Research Center in New Haven, Conn. "We should very carefully avoid making it seem as if overweight people are responsible for environmental decline."

"Obese people have enough issues to deal with without being demonized for their impact on the environment," agreed Keith-Thomas Ayoob, pediatric nutritionist and associate professor at Albert Einstein College of Medicine in New York. "The truth is, all people are an environmental burden.

"It is offensive, and I'm not overweight," he said. "I hope the writers are not in the position of seeing patients. They must have missed the lecture on bedside manner."

A Growing Environmental Impact?

Edwards maintains the rationale for his calculations is solid. Out of the roughly 6 billion people alive today, about one billion live in developed countries like the United States and the United Kingdom. It is in such countries that obesity rates are the highest. Edwards and his colleagues created a hypothetical model of these 1 billion people using the U.K. population as a template.

The researchers then divided the total amount of greenhouse gases generated by the world's population -- about 42 billion tons -- equally among the world's population. By this method, each billion-person segment would be responsible for about 7 billion tons of greenhouse gases every year. Edwards estimated that one-fifth of these greenhouse gases are generated through food production -- in total, about 1.4 billion tons.

But assuming that roughly 40 percent of this population is overweight or obese -- the current figures in the United Kingdom -- the 18 percent increase in food demand means that the total amount of greenhouse gases emitted through food production climbs to 1.66 billion tons.

According to these figures, an additional 250 million tons of greenhouse gases may be released every year to sustain an ever more obese population.

"As the population is becoming heavier, more food energy is required in order to maintain that mass," Edwards said. "This is not pointing the finger at people with a BMI [body mass index] over 30. ... I think that the population has the responsibility to be aware that we are seriously impacting greenhouse gas emission by our weight. These are basic physics equations."