The Environmental Foodprint of Obesity

Emissions of greenhouse gases (GHG) are linked to global warming and adverse climate changes. Meeting the needs of the increasing number of people on the planet presents a challenge for reducing total GHG burden. A further challenge may be the size of the average person on the planet and the increasing number of people with excess body weight. We used data on GHG emissions from various sources and estimated that obesity is associated with similar to 20% greater GHG emissions compared with the normal-weight state. On a global scale, obesity contributes to an extra GHG emissions of similar to 49 megatons per year of CO2 equivalent (CO(2)eq) from oxidative metabolism due to greater metabolic demands, similar to 361 megatons per year of CO(2)eq from food production processes due to increased food intake, and similar to 290 megatons per year of CO(2)eq from automobile and air transportation due to greater body weight. Therefore, the total impact of obesity may be extra emissions of similar to 700 megatons per year of CO(2)eq, which is about 1.6% of worldwide GHG emissions. Inasmuch as obesity is an important contributor to global GHG burden, strategies to reduce its prevalence should prioritize efforts to reduce GHG emissions. Accordingly, reducing obesity may have considerable benefits for both public health and the environment.