Every packaged food in your fridge or pantry has a nutritional label, outlining the food's calories, nutrients and ingredients (among other info). But what if that label also displayed each item's exercise equivalent?
Could you enjoy some chocolate if you're being reminded it'll take about 30 minutes of running to burn it off? Probably not. Though it might help you eat less, labeling food with exercise equivalents can be problematic and may promote unhealthy relationships with food and fitness.
The Science Behind 'Exercise Labels' on Food
Though standard nutrition labels are informative, they have a limited effect on purchasing and eating habits because most people don't totally understand the meaning of calories and macronutrients and how they relate to energy expenditure.
So in a December 2019 study published in the Journal of Epidemiology & Community Health, British researchers reviewed 15 studies that looked at the Potential Effect of Physical Activity Calorie Equivalent (PACE) food-labeling system.
These labels typically display the total calories, followed by the amount of running and walking needed to burn those calories off. For instance, a bar of milk chocolate was labeled with a bright red box, reading: 229 calories. The next box displayed a walking stick figure with 42 minutes written below. Then, the final box showed a running stick figure with 22 minutes.
When compared against standard food labels (or no label at all), PACE labels resulted in significantly fewer calories consumed.
The Problems With These 'Exercise Labels'
Food labels with exercise equivalents may be effective in helping people cut calories, but that doesn't make them fool-proof. The labels don't consider that we all burn calories at different rates, says Kelly Plowe, a Los Angeles-based registered dietitian.
The amount of calories your body burns depends on your metabolism, the process by which your body converts calories to energy, according to the Mayo Clinic. And the speed of your metabolism depends on factors like genetics, body composition and age. So the amount of running it takes for one person to burn off a chocolate bar may vary dramatically for another.
PACE labelling also fails to take food quality into account, Plowe says. "One problem is that much like calorie counting, PACE doesn't take into account the quality of the food you're eating. For instance, a serving of nuts may require the same amount of time walking or running to 'burn it off' as a serving of chips or a cookie."
This can cause consumers to avoid higher-calorie, nutrient-dense foods like avocados, olive oil or pistachios, opting instead for lower-calorie, less healthy options. Although a calorie deficit is crucial for weight loss, you still need to consider the vitamins and nutrients in your food to prevent nutritional deficiency.
But for Plowe, her biggest concern with PACE is the potential harm that it can do to consumers' relationship with exercise.
"Exercise labels" feed into the ideology of exercise as punishment for eating certain foods (or eating at all), Plowe says. "I feel like we're getting to a place where the message is finally getting out about all the other reasons to exercise — mental health, stress reduction, bone health, cardiovascular health, etc — and to me, this feels like we're taking a few steps back."
And reducing food to nothing more than calories can lead to restrictive eating behaviors, disordered eating like obsessing over balancing calories and exercise expenditure. This can cause people to ignore hunger cues and choose foods solely based on calories (missing out on foods they love). Similarly, people may only choose forms of exercise that burn the most calories, rather than modalities they truly enjoy.
Developing a Healthy Relationship With Eating and Exercise
Understanding calories and energy expenditure is important to overall health, but obsessing over the two won't do you any favors. Though it can be hard to reframe these obsessive thoughts, start by focusing less on quantity and more on quality, as well as how both food and exercise can benefit your body outside of your weight.
Your diet should prioritize fruits, vegetables, whole grains, lean protein and healthy fat, but balance is crucial. "There's absolutely room in there for other foods that we love that might not be as nutritionally balanced like ice cream or potato chips — it's just about making sure it's balanced and not getting in the way of eating all of these other healthy foods," Plowe says.
Where your exercise is concerned, opt for activities you love that make you feel physically and mentally energized, just as with your diet. Instead of choosing foods and fitness that can cancel each other out, fuel your body with foods that will support your training.