There are a lot of “sacred cows” in nutritional science, none more so than the ubiquitous calorie hypothesis. Ask any ordinary nutritionist, dietary consultant, doctor, or medical researcher how people get fat and you will likely hear the same answer: People get fat because they take in more calories than they burn.
That’s it. No discussion. No question. No problem.
Except it’s wrong. And it is dangerous.
If you ask any of these same folks HOW this happens, HOW excess calories results in fat accumulation, you’ll get less consistent and less confident answers. Some of them will throw out terms like “thermodynamics” or some other such ideas. Some will, flat out, not be able to explain how it happens, but they will all stick to their original answer.
The reason they are not really able to explain HOW excess calories adds to body fat is because there is no biological mechanism available to accomplish this feat. There is no molecule, no hormone, no enzyme available in the human body that takes “excess” calories and stores them as fat. It just doesn’t happen.
Let’s break it down a little more. A calorie isn’t a physical thing, it’s a measurement of energy. It measures the amount of energy needed to increase one cubic centimeter of water one degree celsius. Typically, when we see the term “calorie”, it is referring to a “kilocalorie”, which is the amount of energy needed to increase one liter of water one degree celsius.
- Cal: measures energy needed to increase 1 cc 1 degree celsius
- Kcal: measures energy needed to increase 1 liter 1 degree celsius
Okay, so a calorie isn’t a thing…it’s a measurement, and it’s not the physiological method of fat accumulation. When you burn calories, you are basically increasing your core body temperature and heating up you body’s water. But that isn’t tied directly to fat (losing it or adding it).
The primary reason that he calorie hypothesis is wrong is that it’s based upon physics, not biology. Using physics to explain biology results in inaccurate and dangerous consequences. For example, let’s use physics to drag the calorie hypothesis to its logical conclusion.
Nutritional breakdown of calories in macronutrients is:
- Carb: 4 kcal/gram
- Protein: 4 kcal/gram
- Fat: 9 kcal/gram
- Alcohol: 7 kcal/gram
Nutritional breakdown of calories in alternative fuels:
- Diesel: 11 kcal/gram
- Jet fuel: 10 kcal/gram
Now, let’s do a thought experiment. Let’s suppose the calorie hypothesis is true (which it isn’t), and let’s suppose we have a test subject, we’ll call him Not Fat Phil. Not Fat Phil wants to get fat. Given the above list of kcal/gram, and using strictly physics as our guide, clearly Not Fat Phil will want to begin a steady diet of Diesel and Jet fuel in order to gain fat. That’s the surest way to get the most calories with the least amount of work.
Obviously not. But why? Because the body doesn’t run on physics. It runs on biological pathways. Drinking diesel in order to gain weight would result in death, because diesel is poison. So the whole idea of calories as the mechanism for weight gain doesn’t work because it’s based on physics, but the body works on biology.
The other, more significant, thing, for me anyway, is that we have no accurate way of measuring exactly how many calories we eat or expend on any given day. As Gary Taubes illustrated, an extra 20 calories per day, over 20 years, will result in 40 pounds of extra fat. If we have to be so precise as to not overeat by 20 calories, the question isn’t ‘Why are people fat?’, but instead, ‘Why isn’t everyone fat?’. Clearly, the calorie hypothesis fails, not only the logic test, but the common sense test, too.
The calorie hypothesis a “sacred cow” that is plainly false because it is based on a flawed paradigm. The truth is, it requires a complete paradigm shift in order to get a start on healthy, consistent, lifelong fat loss.