For decades we’ve heard that the secret to weight loss and maintenance is calories in–calories out. Is that idea changing?
Yes. We’ve started to take a more holistic view of nutrition and health, and there’s an understanding that the quality of food is more important than calorie counting. Back when I was studying nutrition at university, we learned that if you eat 3,500 calories over and above what you need in a day, you’re going to gain one pound. It’s not that this is untrue, but it’s extremely simplistic. Calories are processed differently depending on which food they come from, individual genetics and gut bacteria.
Let’s backtrack. What exactly is a calorie?
A calorie is the amount of heat needed to raise the temperature of one gram of water by one degree Celsius. It was actually first used to measure efficiency in steam engines. The concept as it relates to food and diet came about in the 1860s, based on the idea that calories are to our bodies what fuel is to fire.
How is a calorie from an apple different than one from a chocolate bar? A calorie is always technically the same, but there are differences relating to nutrition. For instance, when you consume a food that has natural sugar in it—like an apple—the sugar is bound up with other nutrients, like fibre and antioxidants. That means it’s going to fuel you for longer than a chocolate bar, where the sugar will be absorbed very quickly—resulting in a spike in blood sugar followed by a crash.
Speaking of fruit, it’s demonized by a lot of trendy diets, like keto and Whole 30. How come?
I hate that. The anti-fruit trend is an extension of the anti-carb movement, and a lot of fruit is high in natural sugar and therefore relatively high in carbs. But as I was saying, fruit has a lot of benefits that simple carbs don’t. It’s absolutely part of a healthy diet. Nothing makes me angrier than when people use fear tactics to sell a new way of eating, leading to more confusion and anxiety around food.
Furthermore, in order to accurately count calories for weight loss, you’d need to know your basal metabolic rate, or how many calories your body burns each day simply to stay alive and keep all your systems running. And unless you’ve done indirect calorimetry, which I can almost guarantee you haven’t—it involves lying with a mask on, hooked up to a very expensive piece of machinery for a prolonged period of time to measure your oxygen intake and carbon dioxide expulsion—you really are playing with arbitrary numbers. Although it’s the “gold standard” of figuring out how many calories you use per day, like anything else, indirect calorimetry can have flaws.
Yes, you can approximate the number of calories you use in a day via equations and apps, but that’s all you get: an approximation. If even the “gold standard” machine can be wrong, then why let some app or equation determine how much you should be eating?
Let’s say that by some miracle, you know exactly how many calories you need to eat per day for weight loss. That’s great, but you’re not out of the woods, thanks to the question of absorption.
We used to think that since 3,500 calories equal a pound, every time you eat 3,500 extra calories beyond what your body needs, you end up gaining that weight. Now we know better: Not all calories are equal like we thought.
When I was growing up, fat was the enemy. Right. That was the era of fat phobia— fat-free salad dressing, diet and processed everything. This goes back to our topic of calories because fat is very calorie-dense. Of course, now we’ve swung in the opposite direction with high-fat, high-protein diets, and processed foods are the bogeyman.
A lot of people don’t even know what “processed” means. Pasteurized milk, roasted almonds and hummus are all processed foods—anything that has been altered from its natural state. But they’re not the same as a Twinkie.
Focusing entirely on calories, instead of the quality of the food you’re eating and how you actually feel before chowing down (hungry, bored, stressed, etc.), can wreak havoc on those precious hunger cues you’re born with. Whether you’re eating just because you “have calories left,” even though you’re not truly hungry, or you’re not eating because you’ve “gone over” your calorie allotment for the day, but you’re actually still hungry, you’re doing the same thing: ignoring what your body is trying to tell you.
Trust your body, because it knows what it needs a lot more than some random number or tracker.
If not calorie counting, what do you recommend for improving our eating habits?
It’s not that I’m totally against calories. I just don’t like the obsession with numbers. Listen to your body and eat what you need to. I want to highlight healthy habits and rituals around eating: preparing your own food when possible, eating with other people and being aware of how marketing can influence food choices. It’s exciting to see those factors being recognized as part of a healthy diet.
Check out my related post: Do you use sauces?