No matter what dishes are on the table this coming season of feasts — which starts off for Americans with Thanksgiving on Thursday — one word will float through everyone’s mind: calories. How many? How sinful? How empty? How delicious? How boring? How much in carbohydrates? In protein? In fat? How soon to the gym? The word is extremely useful — and for that we should be grateful. Calories help us visualise ourselves and our physical exertions numerically. I had so much of this, so I need to work it out by expending that much energy. We are constantly calculating — accurately or not, consciously or not — how the first law of thermodynamics operates so that we can retain or amend our body image. Or blame the numbers for how we look.
Entire industries have emerged to attach calorie counters to our wrists and ankles. When pop idols divulge their favorite recipes in celebrity magazines, complete with caloric measurements, we can become a little more like them — by ingesting the same numbers. OK. That last example is a little creepy. Calories, in any case, turn us into manipulable equations: Eat this, work out, step on the scales... and voila!
But it’s a slippery concept. First, it’s really only been used for food since the late 19th century. In 1887, Wilbur Olin Atwater, an American chemist wrote “The Potential Energy of Food,” an article that proposed using the measure — “the amount of heat which would raise the temperature of a kilogramme of water one degree centigrade (or a pound of water of water 4 degrees Fahrenheit)” — for the energy contained in food. French and German researchers had used the term but, while it was in some English dictionaries, the word wasn’t yet a popular notion.
Atwater changed that when he got the US Department of Agriculture on board in 1896. It published his paper The Chemical Composition of American Food Materials which would be a model of USDA nutritional information going forward. Atwater had calculated the “fuel value per pound” of various cuts of beef, veal, pork and mutton by putting students at Wesleyan University — where he was a resident scientific guru — through his “respiration calorimeter.” For example, beef rump, “very lean” had an average of 710 Calories per pound.
The capital C is important. Even though common American and British parlance now puts the word in the lower case, there was once a distinction between Calorie and calorie. Simply put, 1,000 calories made up one Calorie. Today, what many people around the world call a calorie was once the Calorie. Atwater’s pound of very lean beef rump would have been a terrifying 710,000 old-fashioned lowercase calories. We should be grateful for orthography, too.
Food packaging in the UK, Europe and elsewhere use “kilocalorie”— kilo being the metric designation for 1,000. It’s a technicality. Almost everyone uses “calorie” colloquially. Everyone except scientists. The calorie — big or little — isn’t officially scientific anymore. While a lot of the world popularly talks about weight control in terms of calories in and calories out, the word that is de rigeur in scientific circles since 1948 is joules. But you won’t catch me talking about joules in company — especially if friends named Julian or Julia or Julie are at the table. I like to eat, but I don’t want to be mistaken for a cannibal.
The French, Australians and New Zealanders — and some European Union countries — are trying to do more than use joules on food labels. In China, Atwater’s pound of beef flesh would be 2,970,640 joules. The number is eyewatering, not mouthwatering. The appearance of immensity of joules figures — even when shrunken into kilojoules — is probably why the popular adoption rate is low. What? I have to run off how many hundred-thousand joules?
I’m pretty certain the persistence of calorie (Atwater’s capitalized version rendered in contemporary lower case) is also because it rolls off the tongue. It’s easier to swallow than joules. Caloric numbers are easier to grasp and comprehend when the recommended daily calories to be consumed are 2,500 and 2,000 for the average male and female, respectively. Dropping “kilo” makes it less nerdy — something you can throw around and argue over at the Thanksgiving table . It’s practically poetic, echoing in salary, cavalry, even Calvary if you think calories are a cross you must bear.