For years, calorie counting has been the holy grail of weight loss. Do the math, and it makes sense. There are 3,500 calories in a pound of fat, so for every 3,500 calories you cut from your diet, you can expect to drop a pound. But once you’ve set a goal to eat a certain number of calories per day, how much does it matter where those calories come from? Sure, salmon has healthier fats than a burger, and sweet potatoes pack more vitamin A than regular fries—good nutrition is more than the numbers, it’s also about nutrients. But even if you only focus on the counts, lately, some experts are questioning whether a calorie is a calorie.
But wait, what is a calorie, exactly? If you’ve ever wondered, it’s the amount of energy required to raise about 2 pounds of water by 1 degree Celsius. That might work for measuring energy in a lab. But in your body? Not exactly.
Your body doesn’t always use all of the calories in the foods you eat. Take almonds, for example. An ounce technically contains 170 calories, but a recent study found your digestive system only soaks up about 129. Nuts are difficult to digest, so little fragments pass right through you, taking tiny bits of fat—and calories—along with them. Almonds aren’t the only example: research reveals you may not absorb as much as 11 percent of the calories from high-fiber foods, such as fruits, vegetables, and whole grains.
It also takes more work to break down certain nutrients, especially protein. When you eat a piece of meat, chicken, or fish, your body has to dismantle the protein piece by piece, into tiny building blocks, known as amino acids. Because that process requires lots of energy, it can take up to six times as many calories to metabolize protein compared to carbs or fat. So even if a bowl of Greek yogurt with nuts and berries contains roughly the same number of calories as a cupcake, you’re likely to store more of the cupcake’s calories as fat.
You might notice that all of these good examples are minimally processed. With whole foods, your body has to do the work. With highly processed foods, a machine has essentially broken down the nutrients for you, so your body doesn’t have to do much to extract the calories. In one delicious-sounding study, researchers at Pomona College fed volunteers cheese sandwiches, using traditional cheddar on whole-grain bread versus processed cheese on white. Their findings? Real cheese and whole grains demanded nearly double the energy to burn.
So say no thanks to fake cheese and classic white bread. The point is that whole foods are the better choice on both counts, because you won’t absorb quite so many calories from them, and you’ll burn more calories breaking them down. Enjoy lots of fruits, veggies, whole grains, and lean proteins, filled with fiber and nutrients, to really make those calories count. And continue to track them! Knowing what a bagel or burger packs in can help you make better choices. But you don’t have to obsess. Instead, focus on quality foods in smaller portions.
This article is not intended to substitute for informed medical advice. You should not use this information to diagnose or treat a health problem or condition. Always check with your doctor before changing your diet, altering your sleep habits, taking supplements, or starting a new fitness routine.