According to a study that appears in the International Journal of Epidemiology, a lean population is much better for the environment than an overweight or obese one. Transport-related emissions will be lower because it takes less energy to transport slim people. Similarly, a lean population will consume almost 20% less food and produce fewer greenhouse gases than a population in which 40% of people are obese (like the U.S.). The researchers estimate that a lean population of 1 billion people would emit 1.0 GT (1,000 million tons) less carbon dioxide equivalents per year compared with an overweight one. In nearly every country in the world, average body mass index (BMI) is rising into the overweight range. As we consider green technologies and approach Earth Day to save our planet, it is something we should seriously consider addressing soon.