A new study - published in the flagship journal of The Obesity Society, reports that increasing average body size among people might further challenge attempts to reduce human-made carbon dioxide emissions.
People with obesity have higher carbon dioxide production from oxidative metabolism than individuals with average weight, according to the study. Having higher body masses also need more food and drinks to produce and transport to consumers.
Similarly, transporting heavier people is linked with increased consumption of fossil fuels. The situation ends up in additional carbon dioxide emissions linked to food production and transport processes.
Obesity globally contributes to approximately more than 700 megatons of carbon dioxide emissions per year or about 1.6 percent of all human-made emissions.
The authors underscored that it is critically crucial that this new information would not lead to further weight stigmatization. People with obesity already suffer from adverse reactions and discrimination, and numerous researches have documented several widespread stereotypes.
"This study makes it [apparent] that we pay a steep price for making [things challenging] to [show] care for obesity," said Ted Kyle, RPh, MBA, founder of ConscienHealth, who was not involved in the research.
Untreated obesity, apart from affecting ones health, may also cause environmental issues, Kyle added.
Physical activity also links with much more carbon dioxide being discharged compared with relaxation. However, Boyd Swinburn of the School of Population Health at the University of Auckland in New Zealand commented on the paper that nobody would ever think of branding people who exercise for hurting the environment.
Faidon Magkos, Denmark's University of Copenhagen, explained that managing obesity could favorably affect the environment as well.
"This [study] has [the necessary] implications for all those [people] involved in the management of obesity," added Magkos - who is among the corresponding authors of the paper.
The researchers used the standard measurements of body mass index (BMI) to assess the impact of obesity on the environment. Obesity falls on the BMI of greater than or equal to 30 kg/m2, while healthy weight falls on the BMI of less than 25 kg/m2.
Calculations were made of the excess greenhouse gas emissions - such as carbon dioxide, methane, and nitrous oxide discharge - from the increased oxidative metabolism, the increased food production and consumption, and increased fuel used to transport the higher body weight of people with obesity.
Researchers said obese people produce an additional 81 kilograms of carbon dioxide emissions every year from higher metabolism compared to a person with normal weight. Obesity is overall associated with about 20 percent higher greenhouse gas emissions when compared to people with a normal weight.
They have also seen an extra 593 kilograms per year of carbon dioxide emissions from more top food and drink consumption and a further 476 kilogram per year of carbon dioxide emissions from car and air transportation.
"Harmonizing data from [prevailing rates of obesity, total energy intake and expenditure, and carbon dioxide emissions from different sources is not [an easy] task," Magkos said. "We [underscore] that our [calculations] are not intended to be [accurate], but rather be reasonable enough," said Magkos.
Swinburn, in the commentary accompanying the paper, said the calculations add a piece of relevant information to the growing literature examining the nexus linking obesity to climate change.
Acting on the underlying drivers of them both is of paramount importance while the contribution of obesity to greenhouse gas emissions is small, Swinburn added.