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- “Metabolic food waste,” or overeating, is damaging the environment, according to a new study.
- Researchers coined the term to describe how obesity, human health, and environmental health are related.
- Some body positivity advocates think the study is biased, blaming individuals and worsening social stigma of weight gain instead of addressing systemic inequality.
- Visit INSIDER’s homepage for more stories.
As warnings of climate change become increasingly dire, more and more research is examining how our lifestyles are contributing to the destruction of the planet. One possible culprit may be overeating, according to a new study published in the journal Frontiers In Nutrition.
Researchers proposed as much as 140 billions of tons of food are wasted worldwide by people eating more than they need to.
“Our position is that food eaten above physiological needs, manifesting as obesity, should be considered waste,” Dr. Mauro Serafini, lead author of the study and professor of human nutrition at Teramo University, told Insider. “It’s a very simple idea. I’m trying to link diet with human health and planet health. Obesity is a clear example of food linked to both.”
But body positivity advocates, including a nutritionist and a personal trainer, argue that targeting obesity puts unnecessary blame on individuals for a global problem, and doesn’t take into account factors like food access and poverty which are related to obesity.
The relationship between weight and calories is complicated
Serafini and his team estimated food waste based on the premise that overeating translates to more fat on a person’s body, leading to obesity. To understand this on a global scale, looked used average body mass index (BMI), or height to weight ratio, in each of 86 different countries, and divided the results into 7 regions. They found that Europe and North America were responsible for the most obesity-related food waste.
Researchers came up with their 140 billion ton calculation by comparing the average BMI in each country with a nonobese BMI. They then translated that “excess weight” into calories. The amount of food waste was estimated based on how many of those calories are in different types of foods, including dairy, vegetables, grains.
Calling it waste is misleading, said Rebecca Scritchfield, a registered dietitian nutritionist and author of “Body Kindness,” a book about developing healthy habits and positive body images without dieting. The study’s focus on body mass index doesn’t accurately reflect how weight gain works, instead reinforcing stereotypes about overweight people, she said.
“I don’t see a study that has weight stigma built in as useful,” Scritchfield said. “The notion that based on what a person weighs, this is how much excess they must be eating, is fundamentally flawed.”
BMI is not always an accurate measure of obesity
The study suggests food waste is anything beyond the needed calories to maintain an ideal BMI, which Serafini’s team defined as the midpoint in the “normal” body weight range.
However, BMI as a measure of obesity is problematic because there’s variability in healthy people that such a generalized measurement can’t account for. It was invented in the 1830s and doesn’t specifically measure excess body fat.
“It’s just a measure of weight to height, not a measure of health,” Kelly Coffey, a certified personal trainer, told Insider.
Someone with a high proportion of muscle, which weights more than fat, could be considered obese by this standard.
Similarly, a high BMI doesn’t necessarily mean that someone eats more. People gain weight based on a complicated combination of factors, including genetics, the types of food they eat, and how much they exercise.
“BMI is not the perfect marker. You have many other more important markers [of obesity], “Serafini said. “But from an ecological point of view, we don’t have anything on this. This paper opens the conversation on obesity as an unsustainable condition.”
Some nutritionists are concerned about the harm of connecting obesity with environmental wastefulness
Although Serafini’s study doesn’t intentionally put the blame on individual people for food waste, Scritchfield says it relies on harmful stereotypes of fat people and implies anyone with extra weight is harming the planet.
“Anything that says ‘your body is a problem’ is fatphobia and that is inherently harmful not only to that person’s health but to society,” Scritchfield said. “Intention isn’t impact.”
She added that the study doesn’t take into account many factors related to obesity, such as that people in poverty may be more at risk because of lack of access to healthy options.
“It makes sense that something that would be bad for the planet would be bad for us,” Coffey added. “But do people who struggle with their weight need more of a reason to be ashamed of what they’re eating? Is that the most useful thing to be looking at?”
Systemic, not individual, impacts are most harmful to the environment
Research has shown that it’s our food system as whole, rather than personal habits, that causes the most environmental harm.
A “climate justice” perspective holds corporations accountable instead of blaming individuals, who may come from impoverished or marginalized backgrounds, according to Mary Annaïse Heglar, director of publication for the Natural Resource Defense Council in New York, writing for Vox.
“All too often, our culture broadly equates ‘environmentalism’ with personal consumerism,” Hegler wrote. “While we’re busy testing each other’s purity, we let the government and industries – the authors of said devastation – off the hook completely. This overemphasis on individual action shames people for their everyday activities, things they can barely avoid doing because of the fossil fuel-dependent system they were born into. “
When it comes to individual impact on the environment, evidence-based improvements often have nothing to do with weight. Simply switching out red meat for a plant-based meal could help, regardless of BMI.
The study offers an important ecological perspective on cultural excess
Coffey hopes people will read the study with with nuance, focusing on creating a culture of sustainability instead of scrutinizing individuals.
“It’s more helpful to look at global overnutrition as an environmental lens than through a body shaming lens. That can be a more productive conversation,” she said. “The bottom line is, if we were all living closer to something like balance with nature, we would all be healthier as a global community. Eat mostly plants, ride your bike, and be nice to each other.”