We strongly believe that all diets works work on the same principle: calories in vs. calories out. If you consume more calories than you burn, you put on weight. If you burn more calories than you consume you lose weight. The question that still needs answering is: what exactly do we mean when we say “calories” and how do we answer it without sounding like Bill Clinton trying to parse the meaning of the word “is?”
Most of us regularly use the term “calorie” yet few of us actually know what a calorie is or how calories are measured.
The less-than-helpful, highly technical answer: one calories is the amount of heat required to raise one gram of water one degree Celsius. Calories are not food specific. Any combustible material contains measurable calories. At the high end, a gallon of gasoline contains over 31 million calories. A standard ballpoint pen contains far fewer. Unfortunately, we’ve been unable to find someone willing to throw his or her pen into a bomb calorimeter in order to accurately calculate this number.
Which brings us to the best-named piece of scientific equipment ever: the bomb calorimeter. This is the machine into which anything from a Twinkie to a ballpoint pen can be placed and burned in order to measure its calories. We’re shocked that no one has tried to change the name. These days, simply Googling the words “Bomb Calorimeter” is probably enough to trigger some automated government spy system to add your name to the TSA No Fly List. And bomb calorimeters look as cool as they sound. Picture an old fashioned whisky still attached to a vintage tube amplifier. Some even display the calories in the same red, LCD letters as 70s alarm clocks. There are, of course, modern companies manufacturing bomb calorimeters encased in plastic that look like oversized laser printers; we think the labs that buy these have no sense of style.
Food, or anything other organic material, is placed into a sealed glass cylinder and lowered into a tank of water at the heart of the bomb calorimeter. The contents of the cylinder are then ignited using an electrical current. This process gives off heat that is absorbed by the water surrounding the cylinder. The amount of heat varies based on what was burned in the cylinder. The calories are determined by the rise in the water temperature. The higher the calories in the material being burned, the warmer the water gets. The remnants of whatever was in the cylinder typically look like the aftermath of the worst Fourth of July barbeque ever. Hotdogs are distinguishable from hamburgers only by shape. If you try to go by taste, neither is distinguishable from the pen.
These days, bomb calorimeters are rarely used for measuring the calories in food. The new standard food industry methodology involves plugging the ingredients and quantities into a database of food ingredients. The database not only spits out the calories, but all of the information required for the nutritional label. We have no idea how this new system compares to the old one. These databases are proprietary and owned by the large food manufacturers and trade organizations. Not only does this sound like a massive conflict of interest, it also means that we cannot directly evaluate them. The most we can say is that having a database estimate your calories sounds a little having your Body Mass Index measured by the weight guesser at the circus. Those guys can be eerily accurate, but the process is far from a reliable replacement for being measured in a doctor’s office.
So, a calorie is a measurement of the heat given off by food as it’s burned to a tiny lump of carbon. Does this mean that 100 calories in carrots is wholly equivalent to 100 calories in corn syrup? For the past 30 years, the answer would’ve been an unqualified yes. Obviously, the carrots are healthier and contain more nutritional value. But when it came to calculating calories consumed, both types of calories were considered to have an equal impact on a dieter’s waistline.
There’s an emerging body of research that purports to show that some calories are worse than others in terms of causing obesity. A good example is a recent study done at Princeton University comparing rats fed high fructose corn syrup to rats fed sucrose from sugar cane and sugar beets. Not surprisingly, both groups of sugar-junkie rats gained weight. However, in spite of the fact that they all consumed the same number of calories, the rats fed corn syrup gained more weight. This was a small study that lasted only a few months. The findings have yet to be verified by other studies. But if the results hold, this insight has the potential to change the way calories are measured.
We wouldn’t be surprised to learn that corn syrup packs a greater punch than other sugars when it comes to weight gain in laboratory rats or even people. The human body is not a bomb calorimeter. We don’t literally burn food for fuel. Instead, nutrients are broken down through dozens of different metabolic pathways. It makes perfect sense that it might take more energy to break down 100 calories in carrots than 100 calories in corn syrup. Ideally, the calorie counts we use for food would take this into account. Net calories—raw calories minus the amount of energy it takes for the average person to break a food down—would be far more useful. Assuming the Princeton study is duplicated, the calories listed for corn syrup should probably rise, while the calories in other sugars might drop slightly. This would allow label-readers to make a more accurate comparison between foods. While we realize that most people ignore calories altogether, we always come down on the side of providing more accurate information.
The studies we’ve seen so far have compared only the effects of high fructose corn syrup with sucrose. We have yet to see anyone compare corn syrup with carrots. In fact, every major food would have to be evaluated before nutritional labels could carry net calories. We’re long way from this happening. For now, we have to rely on old-fashioned calories—technically kilocalories—as determined by a proprietary database that hopefully contains the results of actually detonating foods in a bomb calorimeter.
For anyone who believes that the type of calories is more important than the quantity consumed we offer the following case study.
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