You. Yes, you, with your finger poised over the download button of some kind of diet or calorie-counting app. Stop it. I know January, a prime time for weight loss resolutions, is right around the corner, and that some of you might be feeling not-so-great about extra pounds gained during quarantine. Others might feel compelled to start 2021 with a fresh slate of healthy eating. Cool. Great. You don’t need a calorie-counting app for that.
If you do a cursory Google search or follow any health and fitness accounts on social media, you’ll find dozens of articles and influencers touting the benefits of counting calories and recommending apps like MyFitnessPal, Noom, LoseIt!, and Chron-o-meter. Many cite studies that say people who keep food diaries are more likely to lose weight and keep it off. But, my friends, keeping a food diary is not necessarily the same thing as obsessively logging every single calorie that you put in your mouth.
The problem with many calorie-counting apps is in how they’re designed. Typically the on-boarding process has you enter your stats, including your height, current weight, goal weight, activity level, and in what time frame you want to lose (or gain) said weight. From there, the app will use some formula to calculate your basal metabolic rate (BMR). If all you did was lie down all day, without moving, your BMR would be the number of calories your body needs to keep everything running. From there, the app will likely generate a daily calorie allowance—a combination of your BMR, minus a certain number of calories based on your activity level and how fast you want to lose weight. This is some complicated math, but unless you opt for indirect calorimetry, a process that involves hooking yourself up to a ventilator for a period of time to measure the heat generated by the gases you exhale, you’re only getting a ballpark figure that may not even accurately apply to your individual body.
Even MyFitnessPal admits in a blog that its estimates are not 100% accurate. Personally, MyFitnessPal told me that to lose about 1 pound a week, I’d have to eat roughly 1,370 calories a day. That’s a little too close to the 1,200 minimum recommended for women, and if you want to go by my Apple Watch, I burn roughly 2,100-2,500 calories a day. (Though I did appreciate that if I logged less than 1,000 calories in a day, MyFitnessPal chided me to eat more.)
So your calorie-counting app is probably giving you a daily allowance that’s inherently flawed right from the jump. Still, if you log calories, even if they’re an estimate, you’ll still get a pretty accurate picture of your caloric consumption, right? No!
While these apps’ calorie databases have vastly expanded over the past decade, anyone who’s ever used them for a few days can tell you about the limitations. If you cook a meal at home, you’re going to have to find the exact ingredient you use and meticulously measure the exact quantity you’ve used of said ingredient to get the most accurate measurement. Then, you have to save it as a recipe. This process, even in an app with a large database like MyFitnessPal, is tedious. Some will let you import a recipe from a website, but that feature doesn’t always work and doesn’t account for if you substitute an ingredient or two. Forget takeout or eating at a restaurant, unless it’s a fast-food chain that provides caloric information. This means that calorie-counting apps can incentivize you to eat packaged foods over healthier, home-cooked meals, simply because they’re easier to log.
Even if you heroically commit to never eating out and meticulously creating logs for all your scratch-cooked meals, ingredient calorie counts are only estimates. No two medium potatoes have the same exact caloric content. How does the app define a medium versus large potato anyway? Unless you use a scale to measure your servings on a per gram basis, it’s extremely easy to over or underestimate your actual intake. (And who’s gonna lug around a scale all the time?) This Atlantic report notes that roughly 30% of people underestimate how much they eat. It also found people tended to exaggerate their healthy food intake. On top of all this, you can’t even 100% trust a nutrition label because the Food and Drug Administration lets manufacturers calculate calories using five different methods and allows up to a 20% margin of error. That 100-calorie snack could actually be as few as 80 calories or as much as 120 calories.
Say a miracle happened and your daily calorie allowance was spot on and you actually got an accurate account of how many calories you ate in a day. According to Scientific American, it’s virtually impossible to accurately calculate how many calories you actually absorb from the food you eat. Different preparation methods will impact how many calories you absorb—you get more from cooked meat than you would raw meat, for example. Fibrous foods are also harder for your body to break down. Your individual gut bacteria might also impact how many calories you absorb. I’ve never, ever come across a calorie-counting app that was able to mathematically account for that.
This is to say nothing of calories burned, the inaccuracy of which is a rant for another day. However, many food-logging apps will add back calories burned to your daily allowance, lending credence to the idea that you can outrun a bad diet if you just exercise enough. That’s not how things work! Running a 10K doesn’t mean you suddenly have 600 or so extra calories to “spend” on three slices of pizza—not if you actually want to be healthy in the long run. A 2014 study in the British Journal of Sports Medicine noted that “physical activity does not promote weight loss” and that it actually does matter where your calories come from. The calories from sugar, fat, and protein will be metabolized differently. Can you use a calorie-counting app to track your macronutrients? Sure. But that app’s not going to be calculating where the calories you burned came from. Plus, whatever calorie burn estimate an app gives you for a given activity isn’t universally accurate either. Two 150-pound people will burn a different number of calories based on how much fat or lean muscle mass they have, and how active they are.
The whole point of food journaling isn’t to obsessively pore over arbitrary numbers. It’s to get a clearer picture of why, when, and how much food you eat—as well as how you felt while eating those foods. To do that, you’re better off just writing down what you eat in a notebook. Calorie-counting apps don’t make the process easier, they don’t explain the nuances of why “calories in, calories out” might not work for you, and they’re not even particularly accurate. The kicker is most people who download a calorie-counting app don’t keep up with it. This 2014 study found that when provided with a free self-monitoring app, only 2.58% of participants were active users and that the majority of those active users were already healthy.
These apps focus on calories because it’s an easy way to visualize food intake, especially when it comes to weight loss. You don’t have to account for the nuances of the human body if you just tell people if they eat X calories they’ll lose Y pounds in Z months. The apps certainly don’t account for the false narratives they promote or the eating disorders they’ve been shown to exacerbate. There’s nothing wrong with wanting to lose a few pounds or with wanting to keep track of your food intake, whatever the reason may be. But instead of wasting time on a calorie-counting app that may only serve to drive you bananas, you might want to consult a registered dietician or your physician to safely and sustainably achieve those goals.