Obesity is complicating the climate-change fight, researchers say, especially as the Earth’s population adds roughly 83 million people of all shapes and sizes every year.
A combination of higher metabolism leading to more carbon dioxide, an additional increase in carbon-dioxide emissions from greater food and drink consumption and the extra output of emissions from fossil fuel-powered transportation, obesity is associated with approximately 20% more greenhouse gas emissions compared to people considered to have a healthier weight.
Researchers in this recent study found that global obesity was estimated to contribute to an extra 700 megatons of carbon dioxide emissions per year, or about 1.6% of all man-made emissions.
Researchers in a recently published study found that global obesity was estimated to contribute to an extra 700 megatons of carbon dioxide emissions per year, or about 1.6% of all man-made emissions. Obesity has been labeled by the Centers for Disease Control and Prevention as an “epidemic” that contributes to a higher rate of heart disease, stroke, diabetes and some types of cancer.
“Our analysis suggests that, in addition to beneficial effects on morbidity, mortality and health-care costs, managing obesity can favorably affect the environment as well,” said Faidon Magkos, of the Department of Nutrition, Exercise and Sports at the University of Copenhagen in Denmark, and an author of the paper published by the Obesity Society.
The concern with weight and carbon emissions was chronicled in a paper by the Obesity Society, a scientific society dedicated to the study of obesity and its treatment. The organization has in the past accepted funding from Pepsi Co.
and has previously had a close relationship with the soda industry through its now-disbanded food industry engagement council.
To arrive at the theory, the scientists started with basic biology: Obese people have greater carbon dioxide production from oxidative metabolism than individuals with a so-called normal weight. To determine “obesity,” scientists calculated body mass index (BMI), which is a person’s weight in kilograms divided by the square of height in meters. The climate/health researchers used the standard definitions of obesity as measured by a BMI of greater than or equal to 30 kg/m2 and normal weight as measured by a BMI reading of less than 25.
But there were other factors to consider beyond exhalation: the researchers assert that maintenance of greater body weight requires more food and drinks to be produced and transported to the consumers. Similarly, transportation of heavier people is associated with increased consumption of fossil fuels, basically an assumption of more driving and less walking or bike riding, which may not be true of all obese people.
The authors emphasized that it is critically important that this information does not lead to more weight stigmatization. People with obesity already suffer from negative attitudes and discrimination, they said.
The authors emphasized that it is critically important that this information does not lead to more weight stigmatization. People with obesity already suffer from negative attitudes and discrimination, and numerous studies have documented several prevalent stereotypes.
“This study makes it clear that we pay a steep price for making it difficult to access care for obesity. Not only does obesity affect the health of the individuals who have it, untreated obesity might also contribute to environmental issues,” said Ted Kyle, founder of ConscienHealth, who was not involved in the research, but provided comment for the Obesity journal.
Physical activity is also associated with much more carbon dioxide being produced compared with rest, but no one will ever think of stigmatizing people who exercise for having a negative effect on the environment, added Boyd Swinburn, who works in the school of Population Health at the University of Auckland in New Zealand, in a commentary on the original paper.
The researchers also conceded that their study is built on what they view as a less-than-precise combination of data from the epidemic of obesity combined with physiology, or measuring total energy intake and expenditure, and adding in tracking carbon dioxide emissions, which can come from a variety of sources.
Swinburn said the estimates add valuable information to the growing literature examining the nexus between obesity and climate change. He added, “While the contribution of obesity to greenhouse gas emissions is small, acting on the underlying drivers of them both is of paramount importance.”
Of course, the debate between weight and health is a complicated one, and a strain on society, exclusive of the question of climate impact.
Most research has shown a consistent association between weight gain and health problems. For example, a 2018 study by the European Heart Journal looked at almost 300,000 people without heart disease who were classified as either “normal” weight, overweight or obese based on their BMI (Find your BMI using this Harvard Medical School calculator.) After four years, the researchers found a direct correlation between higher BMI and a higher risk for heart attacks, stroke and high blood pressure. Of particular concern is the visceral fat stored at waist level, in the abdominal cavity, which can surround vital organs.
What is clear is that the impact of where health meets climate change and vice versa is coming under increased scrutiny. A new report from the World Health Organization warns that the climate crisis is already spreading disease and could also trigger anxiety, depression and PTSD.