If you are at all familiar with popularized weight loss and nutrition science, you may know that there is something of a controversy over the question in the title. I myself have battled with this question for years. Certainly by now you have at least heard the phrase “a calorie is a calorie.” Out of context I guess it doesn’t make any sense, so let me explain.
A calorie is a unit of energy, specifically the amount of energy required to increase the temperature of 1 gram of water by 1 degree Celsius. The “calories” we refer to in our food are actually kilocalories, sometimes abbreviated to “kcal.” We consume food, or substances that provide calories, because we need energy of a certain caloric amount to live and to perform any activity, from sleeping to rock-climbing to ballroom dancing to digesting food itself. The macronutrients known as carbohydrates, fat, and protein provide calories. We consume food to get noncaloric micronutrients too, of course, but more on that later.
The question in this controversy is whether consumption of a calorie of energy from one food or nutrient is equivalent to a calorie from another food or nutrient in terms of weight and health. In my mind, there is no doubt that the direct cause of weight gain is calorie imbalance. When you consume more calories than your body burns, the excess energy is typically stored as fat, unless you’re exercising to build muscle. This will happen whether you eat 3500 calories of milkshake or 3500 calories of broccoli.
But the debate is not really whether the direct cause of obesity is calorie imbalance, but whether it is the only or root cause of obesity. The food industry would have you believe that you can eat anything in moderation as part of a healthy diet, but I can firmly say that there are inequalities in different foods that influence how much of them you will consume. This is why the phrase “a calorie is a calorie” is misleading; the sweet, creamy, and calorically dense milkshake inherently discourages moderation, while i’m sure no one has ever been compelled to consume enough broccoli to contribute to weight gain. And I’m not talking about cream of broccoli soup.
Not only that, but caloric equivalents of different foods are certainly not equal in terms of health, regardless of how they influence calorie balance. Sugar, which usually enters our diets as cane, beet, or corn sugar (including high fructose corn syrup), is half glucose (our default energy molecule) and half fructose. I finished a book today called Fat Chance, in which I learned a whole lot about the havoc wreaked on the body by unadulterated fructose. In nature, sugar is accompanied by fiber (see my recent post), which stunts its toxic effects. But ubiquitous in fiberless processed foods, the fructose part of sugar is immediately turned to fat by the liver, is addictive, and is a major contributor to metabolic syndrome (any combination of insulin resistance, heart disease, diabetes, high blood pressure, etc.) independent of weight. This is why it’s so much easier and more common to overeat M&Ms than to overeat strawberries. This is why sugar sweetened beverages are a primary driver of the epidemics of obesity and chronic disease. You can learn more about the dangers of sugar by watching this video presented by the brilliant author of Fat Chance, Dr. Robert Lustig.
I used to count calories to lose weight and then to maintain my weight. It was effective for me, but it also made me nuts and wasted my energy. I also was trying to eat healthier foods–I’m sure if I had eaten junk counting calories wouldn’t have made a difference. In the last year or so I realized that the most important thing wasn’t staying under my daily calorie limit, but really limiting the amount of calories from processed food and sugar.
As I’ve been writing consistently, the key is eating real food over processed food as much as you can. Real food is what our bodies are made to eat, and of what we won’t overeat enough to make us fat and sick. Once I began to compose the more of my diet of foods that don’t come in a package with nutrition information, the need to count calories actually disappeared. I had struggled to maintain my weight loss for three years by counting calories, but after I started eating a whole food, plant based diet, I dropped a couple pounds without trying.
Ultimately, calories count. There’s no doubt about that. And if you’re just eating a little too much, then calories might be the right focus for you. But the broader issue affecting the millions of morbidly obese Americans is the quality of calories, not the quantity. If we work to change what people, and especially children, are eating, then I believe how much they are eating will be much healthier. And so will the people themselves.
What do you think? Is a calorie a calorie?