A good place to start our story is with food, which nourishes us and keeps us alive. One concept that has dominated the global conversation on nutrition in recent times is 'the calorie', the subject of much controversy. We count calories, compare them, choose them, condemn them, but most of us know very little about what has had such a significant impact on the way we eat and relate to food.
The calorie was originally a unit of heat, defined as the amount of heat needed to raise the temperature of 1 gram of water by 1 degree Celsius. A bizarre experiment conducted in 1896 by a professor at Wesleyan University, Wilbur O. Atwater, brought the calorie, as we now know it, into the spotlight.' For the study, a graduate student climbed into a calorimeter, an airtight metal chamber previously used to measure the energy created by engines and explosives.
They measured the volume of bread, baked beans, milk, mashed potatoes and steak, while measuring their energy output in terms of thermal energy. As a result of this experiment, foods were assigned values in terms of calories for the first time, effectively turning eating into a study of mathematics. The idea of the calorie first became a tool for the US government to achieve 'nutritional efficiency', especially when it came to feeding an industrial workforce, prisoners and school children. Restaurants in New York listed the calorie value of dishes on their menus alongside the recommended daily calorie intake for different walks of life! During World War I, calories played a key role in food rationing and export.
While At water used his discoveries to discuss achieving physical efficiency, it was doctor and author Lulu Hunt Peters who, in 1918, began to popularise the idea of counting calories for weight loss. Through her weekly column and an accompanying book, Diet and Health: With the Key to Calories, she advocated subtracting calories from one's diet in order to lose weight. At a time when skinny was 'in,' her approach reduced food entirely to its component calories. Peters famously wrote, 'Next, you're going to eat the calories of the food. Instead of saying a slice of bread, or a slice of pie, you'd say 100 calories of bread, 350 calories of pie. "After Peters, it seems, there was no turning back. Calories became the measurement everyone looked to.
To lose, or in some cases, gain, weight, based on the idea that consuming fewer calories than you expend results in weight loss, while consuming more than you expend results in weight gain.
Both Atwater and Peters contributed to the rise of nutrition as a quantitative science that in some ways took food traditions out of their rich social and cultural contexts and histories.
One of the most commonly held beliefs for a long time was that a calorie is a calorie, no matter where it comes from. In a 1903 ad for beer in the Washington Post it was claimed that a glass of their beer was roughly equivalent in calories to a glass of milk, and was, therefore, 'sufficient to furnish abundant energy to the human machine.' In fact, At water didn't consider green, leafy vegetables to be healthy—he barely considered them food—because they contained so few calories that they weren't efficient sources of energy in his eyes.
One of the most significant repercussions of the calorie counting trend was the vilification of fat in the year of 1980s. The macronutrient, fat, has the misfortune of sharing its name with an adjective for people who are overweight, and as a result we've always looked at it with some suspicion. Also, being more calorie dense than other macronutrients, it was assumed that fat was the main cause of weight gain. This led not only to the rise of processed carbohydrates in our diets, which we now know aren't very high in nutritional value, but also to people choosing low-fat or fat-free products, thinking these would help them keep their weight in check. The problem, however, is that most low-fat products are high in sugar. Thinking they were making a healthy choice, people avoided fries, but made their sodas bigger—a soda. , which might be ten tablespoons of sugar!
The thing about calories is that, sometimes, it's more about quality than quantity (like so many things in our lives!).
