The History of the Calorie

April 26th, 2019 | Posted in Info

Goodbye to Calorie Counting

This month’s blog posts will examine the calorie. We’ll examine why and how it became the touchstone for measuring food intake and the main focus of the diet industry and government policies on health and obesity.  In 19 Reasons Why Calorie Counting Doesn’t Work we’ll look at the problems with this system and in Not All Calories are Equal we’ll look at how the calories from different macronutrients behave differently in the body.

But first let’s look at the history of the calorie and how it came to be so prominent in our thinking about food.

The History of the Calorie

Calories were first used to measure the efficiency of steam engines. One calorie is the energy required to heat 1kg of water by 1 degree Celcius. The word calorie comes from the Latin word calor, meaning heat

In the 18th century calories were first used to describe the energy that fuels the body in the same way that wood fuels a fire but it wasn’t until the 1860s that calories were used to measure the energy in food and the energy expended by the body. In the 1890s it was established that a gram of carbohydrate or protein provided 4 calories of energy, while a gram of fat provided 9 calories. These remain the standard for measuring the calories in foods.

By the 1930s calories were fundamental to the way people and governments thought about food. With the relative prosperity of the 1960s in the western world, along with increasingly sedentary jobs and the availability of processed foods, obesity was becoming a health concern. Because fat carries 9 calories per gram, more than twice as much as protein or carbohydrates, it seemed the best way to reduce calorie intake was to reduce fat intake. This led to low fat foods, often high in processed carbs and sugars, being considered suitable for people trying to lose weight. It is also easy to demonise foods called “fats” when it is fat we are trying to lose from the body.

The move towards low fat foods being considered healthy coincided with a dramatic rise in obesity, cardiovascular disease and type 2 diabetes from the 1970s onwards.

Many dieters have religiously counted calories and reduced their intake only to find that after an initial weight loss their weight plateaus and eventually they pile the weight back on.

Read 19 Reasons Why Calorie Counting Doesn’t Work and  Not All Calories are Equal to find out why this is such a common pattern.