Researchers at the London School of Hygiene and Tropical Medicine published a study showing that, because of food production and transportation factors, a population of heavier people contributes more harmful gases to the planet than a population of thin people.

Given that it takes more energy to move heavier people, transportation of heavier people requires more fuel, which creates more greenhouse gas emissions, the authors write.

“The main message is staying thin. It’s good for you, and it’s good for the planet,” said Phil Edwards, senior lecturer at the London School of Hygiene and Tropical Medicine.

The study offers this novel approach to the global warming problem as U.S. lawmakers discuss the future of climate change legislation. This week, the the House Energy and Commerce Committee is scheduled to begin on a comprehensive energy and climate bill. On Friday, the Environmental Protection Agency announced that six greenhouse gases pose potential health hazards, an announcement that could prompt the regulation of the gases.

More than 1 billion adults worldwide are overweight, and about 300 million are obese, the study said. Generally, the body mass index, a measure of obesity, is increasing in most countries worldwide, from China to European countries to the United States.

BMI is going up because of the availability of food and motorized transportation, Edwards said. People are less active now than they were 30 years ago, and the prevalence of fast food has given people less healthy, more energy-dense options.