Why a Calorie Isn’t Just a Calorie

Have you ever tried to count calories? How long did you last? Did it prove to be a successful solution in your goal to gain or lose weight? Time and time again I see individuals strive to calculate every morsel of food they consume and never get the results they were looking for. This is because there is more to weight management than just counting calories. Healthy eating is more than just a numbers game. A calorie isn’t JUST a calorie. The idea that your weight is only about balancing calories in and calories out is oversimplifying the facts. Let’s take a closer look.

What is a Calorie? A calorie refers to the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius. If physics isn’t really your thing, check out this quick video to better understand the meaning of calories.

Where Do Calories Come From? Calories in our diet come from the macronutrients: carbohydrate, protein and fat. 1 gram carbohydrate = 4 calories, 1 gram protein = 4 calories and 1 gram fat = 9 calories. As you can see, fat is the most “calorically dense” of the macronutrients. This is why most diets eliminate fat first and focus on consuming more carbohydrates and protein (we’ll get to more on why this isn’t working in a moment).

Calories In = Calories Out and the Laws of Thermodynamics: We believe that if you take in more calories than you expend, you will gain weight and if you take in fewer calories than you expend you will lose weight because of the laws of thermodynamics. The first law of thermodynamics is the law of energy conservation – simply put, energy cannot be created or destroyed, it can only change form. In a speech given by Gary Taubes at the University of Colorado Medical school in 2013, he states that, “the laws of thermodynamics tell us nothing about obesity. They’re completely irrelevant. Why is it that from the moment you enter medical school until you retire, the only condition you will ever diagnose with a physics textbook is obesity. This is biology folks. This is endocrinology. It’s physiology. Physics has nothing to do with it.”

In his book Why We Get Fat, Taubes goes on to explain that the calories in, calories out theory is based on association and tells us nothing about causality. You can say that someone gets fat because they eat more calories than they expend but that’s a given. It doesn’t tell us WHY that particular individual eats more calories. We are missing a key piece of the puzzle. In the words of Jonathan Bailor, author of The Calorie Myth, Biology ≠ Math.

Our body naturally balances our calories in and calories out. This is why our ancestors were able to maintain stable weights without ever knowing what calories were or how to count them. How is this possible? Our body naturally strives for a state of equilibrium. Think of it this way. Mathematically speaking, 1 lb = 3500 calories. Suppose you were to eat 35 extra calories today. Easy right? That’s one bite of a sandwich or a third of an apple. If you continued this for the next 10 years, mathematically your body weight would increase by 36.5 lbs. Or what about this. If over the past 10 years you have been able to maintain your body weight around the same number, math tells us that you must have done so by consuming the exact number of calories needed for that weight every day (not 5, 10 or even 35 calories more or less). This sounds absurd right? No one that has maintained a stable body weight for 10 years has done so because he or she has paid attention to every morsel of food eaten every hour for every day for 10 years. There’s clearly more to the story. Again, biology is not the same as math.

Food Quality and Metabolism: Not all calories are created equal. Anyone can tell you that eating 100 calories of candy is not the same as eating 100 calories of broccoli. Mathematically they are the same, but nutritionally they are not. Even more importantly is the fact that all of the macronutrients we ingest (carbohydrates, protein, and fat) are METABOLIZED by the body DIFFERENTLY. We cannot let math oversimplify this fact.

What is metabolism? Metabolism is defined by the sum total of all chemical processes in the body. Simply put, it’s the body’s chemical efficiency to either burn energy (i.e. calories) for fuel or to store it as fat. As previously mentioned, our body naturally strives for a state of equilibrium. If you are consuming more calories, your body is able to burn those calories as energy more efficiently than storing them as fat and you will in turn naturally desire to be more active (eat more, move more). If you are restricting calories (because you are either starving or on a diet), your body will be more efficient at storing these calories as fat (for survival) instead of burning them for fuel (eat less, move less). This is why many dieters feel tired and lethargic when restricting calories.

Hormones (Insulin & Glucagon): Hormones are responsible for regulating metabolism. Simply put, they are the ones deciding what to DO with the macronutrients you eat. Take carbohydrates for example. When you consume a carbohydrate, it gets converted into sugar (glucose) during digestion and sent into the blood stream for the body to utilize. Therefore, carbohydrates increase your blood sugar. The pancreas produces insulin (a fat-storing hormone). Insulin helps cells burn the sugar for fuel where needed and sends the remaining sugar into fat stores. Here is where you can see how a diet high in sugar/refined carbohydrates and little to no activity can lead to increased fat stores (i.e. weight gain).

Protein and fat on the other hand are metabolized differently than carbohydrates. They do not have the same affect on blood sugar as carbohydrates do. When blood sugar is low, the pancreas produces glucagon (a fat-burning hormone), to convert stored fat into sugar. This sugar is then used as fuel throughout the body where needed. If you work your way backwards from here you can see how a diet focused on protein and fat with limited carbohydrate can lead to decreased fat stores and weight loss.

Solution: Eating a balanced diet of carbohydrate, protein and fat at every meal will ensure your body gets the fuel it deserves. Pairing carbohydrates with protein, fat, and fiber will decrease the affect the carbohydrates have on your blood sugar. Ultimately we want balanced blood sugars all day long. If are experiencing a blood sugar rollercoaster (craving sugar, crashing after a meal, never feeling satisfied, feeling tired, moody or irritable), reassess your plate at mealtime. Ask yourself, do you have a balance of protein and fat to go with that carbohydrate?

Ultimately we cannot oversimplify nutrition with math. We need to support our own, unique underlying biochemistry and fuel our body with foods that will give us energy and help us maintain a healthy weight, naturally. Don’t be fooled by 100 calorie snack packs and diet sodas. It’s all about quality of food, not quantity. Your body knows the difference between 200 calories of high fructose corn syrup and 200 calories from an avocado. So next time you reach for a snack, choose wisely and remember that a balance of carbohydrate, protein and fat is ideal.

A Calorie Isn't Just a Calorie


  1. Joe Harrison

    This is a pretty ignorant article. The laws of physics are universal and apply to everything, otherwise they wouldn’t be laws. An energy system must be in balance or it violates the first law of thermodynamics. If we can accurately calculate energy in (caloric intake), and we gain weight, that means we’re incorrectly calculating energy out. Calculating energy out on an individual basis is quite difficult. Mitochondrial content in muscle is a big component of metabolism, the single biggest contributor to caloric consumption. How efficient your mitochondria convert fuel into ATP is an important factor that needs to be calculated as inefficient conversion is given off as heat. ATP production, muscle mass, exercise, age, caloric intake all impact metabolism and make the calories out measurement incredibly variable from person to person. But make no mistake, calories in always equals calories out. An energy deficit will deplete adipose stores (and eventually other energy rich tissue like muscle), and an energy surplus will increase fatty acid content in adipose tissue.

Submit a Comment

Your email address will not be published. Required fields are marked *