The Continuing Calamity of the Calorie Con
The time has come for all of us struggling to lose weight and stay thin to reject the daily dose of nonsense we get from self-proclaimed experts. We can only take control of our diet if we first dismiss all the "advice" that leads to nothing but failure.
"What you eat makes quite a difference. Just counting calories won't matter much unless you look at the kinds of calories you're eating [emphasis added]." That quote comes from cardiologist Dr. Dariush Mozaffarian as cited in The New York Times.
In that same article, Dr. Mozaffarian goes on to slay a straw man by noting that, "Also untrue is the food industry's claim that there's no such thing as a bad food."
I do not know Dr. Mozaffarian but I am sure his motives are good. But nobody is helped when he and other experts speak loosely and forget basic biology. The doctor is certainly in good company, because his claims or those similar to them are widely believed to be true, often mentioned by prominent doctors on television and frequently shouted at us from the pages of tabloid newspapers. But these claims are wrong, factually, demonstrably, false. The first claim about "kinds of calories" is patently incorrect, confusing the calorie as a unit of energy with the quality of food as a source of nutrition and health. The second claim is absurd: of course there is bad food, but that has nothing to do with calories as we will soon see.
So what do we do in the face of this constant barrage of bad advice? Well, knowledge is power, and we can overcome the allure of easy promises, false claims and bad biology with just a little insight into the world of the calorie.
A calorie is a unit of energy defined as the amount of energy required to raise the temperature of one gram of water by one degree. There are no more "kinds of calories" than there are "kind of degrees Fahrenheit" or "kinds of electron-volts." How silly would I be if I claimed that one gallon of water occupied a different volume than another gallon of water sitting right next to it? Well, the claim that there are different kinds of calories is equally ridiculous. A defined unit of measurement does not change by what is being measured or when the measurement is taken.
Let's get formal for a minute. In the definition of a calorie above I refer specifically to degrees Celsius at one atmosphere, and the gram calorie (or small calorie) versus the original definition based on the kilogram. Note that when discussing food energy the common unit is actually the kilocalorie, but the prefix is almost always dropped, so people say calorie when meaning kilocalorie. Also, the amount of energy required to raise water temperature depends on the starting temperature, making the definition vulnerable to variability. For the sake of simplicity, I mean calorie, not kilocalorie, and I mean that one calorie is equal to 4.2 Joules.
Nowhere in the definition of a calorie is there any mention of the source of fuel needed to raise the temperature of one gram of water one degree. To heat the water you can use a BIC lighter, burn coal or torch banana peels. The only important thing is the total energy necessary to raise the water temperature by the specified amount. Burning one calorie is burning one calorie no matter what is being consumed by the fire.
Therefore, we come to an important conclusion: one calorie of carbohydrate is exactly equal to one calorie from fiber, which is precisely equal to one calorie from saturated fat. One calorie of fruit equals one calorie from a fudge bar. As a unit of energy, a calorie remains constant, always, across all foods. That is a fact of definition, and cannot be disputed anymore than you can dispute the length of an inch or centimeter. A calorie is a fixed and defined unit of energy. Period. There are not different kinds of calories just like there are not different kinds of inches. An inch will always denote the same defined distance between two points no matter what is being measured. The calorie will always denote 4.2 Joules, no matter in what food the energy content is being measured.
Dr. Mozaffarian and many of his colleagues in the medical profession make the classic and common mistake of confusing calories with food quality, mixing up the energy content of food with its nutritional value, two completely independent measurements. There are not different kinds of calories! Remember one calorie equals a defined and set amount of energy, no matter if that calorie comes from donuts or Dijon mustard. A calorie is always a calorie. An inch is always an inch. A gallon always defines a specific volume.
If you consume one pound of fudge you will consume more calories than if you eat one pound of broccoli because calories are more densely packed into the sweet. But if you take a small nibble of fudge equivalent to one calorie or a big bite of broccoli equal to one calorie, you will have consumed one calorie whether that came from the vegetable or confection. In terms of energy content, it matters not whether your calorie comes from fudge or broccoli. In terms of nutritional health, the source of food matters greatly; to remain healthy you need a balance of protein, fiber, vitamins, fats, and other essential nutrients, and you must get those from the foods you eat. That is why there are indeed "bad" foods, those that do not contribute to nutritional health, or worse, exacerbate a decline in health such as saturated fats that contribute to coronary disease.
We all need to be clear about this: in terms of weight loss, all that matters is calories in versus calories out, in spite of "expert" claims to the contrary. (All the many factors that can impact how many calories you burn are important but not the focus here). This equation is a matter of thermodynamics: when calories in equals calories out, you will not gain weight. Any deviation from that truth would mean you have developed the perpetual motion machine, getting free energy from nothing. In terms of health, you must make sure those calories contribute to your well-being by providing all the essential nutrients. The energy content of a chunk of food is a completely separate measurement from that food's nutritional value.
I pound home this point because the calorie concept is so pervasively misunderstood that any intelligent discussion of weight gain typically goes downhill from there. The indisputable bottom line is that when discussing weight loss (ignoring for the moment nutritional health), and weight loss alone, the source of calories you consume does not matter. Because a calorie is always a calorie, no matter the source. The only thing that matters for weight control is total calories you eat, regardless of where they come from, compared to total calories you burn (no matter how you burn them). That is a consequence of biology and physics that cannot be changed by wishful thinking or urban myths. There are no "kinds of calories." A calorie in healthy food is identical to a calorie from unhealthy food; the choice of what foods we eat to constitute our total calorie intake is entirely up to us.
Counting calories always matters when trying to lose weight; but we must eat well if we wish to maintain our health while counting the total calories we consume. I would lose weight if I consumed nothing but 1200 calories of fudge every day. I'd be sick, too, because I am not getting my essential nutrients, but I would lose weight. Energy in must be less than energy out if we wish to lose weight; energy in must equal energy out if we wish to maintain our weight; and energy in must exceed energy out if we wish to gain weight. We count calories to control weight; and we make sure the foods we eat making up those calories are healthful so we get our balance of essential nutrients. No other formula works. It really is that simple.
Next time you hear an expert talk about "kinds of calories" change channels and run for the hills.