If you're reaching for a snack, would you hesitate if you knew how much exercise it would take to burn off that bag of chips, can of soda, or candy bar?
Some researchers think the answer is yes, according to a new study, published Tuesday in the Journal of Epidemiology & Community Health.
The new research, funded by Loughborough University in England, suggests such labeling will prompt people to make healthier choices, potentially helping to curb popular-wide health problems with junk food like obesity, diabetes, and heart disease.
But other research and some nutrition experts suggest the strategy could backfire, harming people most at risk of poor nutrition like those at risk for eating disorders or those living in poverty.
Labeling foods with exercise equivalents could help people eat up to 200 fewer calories per day
For the study, researchers from Loughborough University, University of Birmingham, and Norwich Medical School looked at 15 published studies on food labels and dietary choices.
They found that in cases where foods were labeled with not only calories but also the estimated exercise needed to burn them off, known as physical activity calorie expenditure or PACE, people consumed an average of 65 fewer calories, but as many as 100 fewer calories, per meal.
The researchers believe this is because people frequently underestimate the number of calories in what they eat and drink, but also how many calories they actually need a day, based on their activity level.
That type of labeling gives "the public all the information they need to make decisions about what they eat," Amanda Daley, co-author of the study and a professor of behavioral medicine at Loughton University, told Insider.
She and her co-authors estimate that if the PACE labeling were broadly applied, based on a the typical eating patterns of three meals a day and two snacks, consumers could eat up to 195 fewer calories per day.
This would be a promising solution to growing concerns about the obesity epidemic, as even a reduction of 100 calories a day could help curb weight gain, according to the researchers.
"People think obesity is caused by gluttony, but it's not. It's all of us eating a little bit too much, every day," Daley said. "So we're trying to keep that in check by giving people context."
However, the study had significant caveats. Most included in the meta-analysis took place in labratories and not in real-life scenarios like restaurants and grocery stores, so it's not clear how people might respond in those settings, though Daley said her team is planning to conduct research in those areas next.
Plus, calculations for calorie burning were made based on the estimated metabolism of an average-sized adult man in the UK, so would be less accurate for people of different sizes, genders, and activity levels.
Some experts worry the strategy could backfire
Not everyone agrees PACE labeling is a good strategy to reduce how much people eat. It could actually harm people most at risk of poor nutrition, such as people with or at risk for eating disorders or those living in poverty, according to registered dietitian Rachael Hartley.
"It sends a message that you have to earn food," Hartley told Insider. "When people focus on calories, it can end up meaning they focus what is the smallest amount they can physically eat, instead of how they can nourish their body adequately."
Instead, it can be more helpful to for people to rely on their own body's cues about hunger and fullness, she said, and being able to meet those needs with high-quality whole foods.
This approach, known as intuitive eating, has been shown to improve both physical and psychological health in fixing people's diet-driven approach to foods.
Equating food with exercise "needed" to burn it off is also an ineffective way to motivate people to exercise long term; in fact, some research shows "body shape" goals actually make people less likely to exercise.
The key to improving the population's health, according to Hartley, is making sure that people not only have information about food, but also access to nutritious, healthy, and filling options.
"It really comes down to giving people access to food instead of more education," she said. "If someone doesn't have time or money to prepare a meal, if all they have access to is a bag of chips, I want them to have access to healthier food choices. I don't want them to have to eat an extra side of guilt and shame."
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If you or someone you know has an eating disorder, call the ANAD Helpline (1-888-375-7767) on weekdays for support, resources, and information about treatment options. In crisis situations, you can get support 24/7 through the Crisis Text Line — just text "HOME" to 741741.
