What Are Calories & How Do We Calculate Them

UPDATED: June 1, 2016

 how to count calories

 Artwork: Elle Muliarchyk.

There is totally a method for how to calculate calories. It's not this secret code that only calorie trackers and food manufacturers know. Like I always say, "sharing is caring." So let's talk about the math behind calorie counting. It could come in handy one day. But first, let's pay homage to a chemist by the name of Wilbur Olin Atwater and get an understanding of what calories actually are.

 Wilbur atwater 1800's

Wilbur atwater 1800's

Wilbur Atwater was an American chemist who specialized in human nutrition and metabolism. He along with two other scientists Edward Bennet Rosa and Francis Gano Benedict developed the "Atwater System" which calculated the energy of foods. Specifically Atwater invented the Respiration Calorimeter. Pieces of food were placed in the Calorimeter and burned to see how much energy it contained. Each unit of energy was dubbed a "calorie."

Calories are units of measurements for energy. Food's sole purpose is to provide our bodies with enough energy to function. Therefore we track our food intake by calorie to insure our bodies have enough to function. This makes dieting and burning fat or gaining muscle essentially a math equation.  The only things we consume that are measured in calories and provide energy for the body are macronutrients called protein, carbs, and fat.

Excess energy gets stored as body fat. It just sort of acts as a energy savings account for the body. If you provide your body with less energy than it needs to function, it will go to those fat stores to burn them and produce energy. Now, it doesn't immediately access those fat stores, that's plan B for your body. Plan A is to convert the food you consume into energy and specifically the carbs. When your body doesn't have enough food or carbs to convert into energy, it will go to the stored fat on your body and burn it. This is why diets designed to burn fat always require a caloric deficit as well as reduced carbs. You have got to get the body to choose plan B for energy and burn your body fat.

When converting food into energy your body will convert carbs first, then fat, then protein. When your body converts all your carbs into energy that's great, when it converts your fat, that's excellent, if you are losing weight. If it gets to the point where it's forced to convert protein, you're in trouble. That is when you begin to lose muscle. Remember, it will only be forced to convert your protein into energy when you have not provided it enough food, or carbs, and you don't have the available fat stores to provide energy. Now let's examine how much energy or calories each macronutrient produces for the body.


Calories/Energy Per Gram

Protein and carbs both produce 4 calories per gram, while fat produces 9 calories per gram.

Throughout a day, if you consume 240g of carbs, 180g of protein and 85g of fat, you will have consumed 2,445 calories.

240g of carbs x 4 calories per gram = 960 calories

180g of protein x 4 calories per gram = 720 calories

85g of protein x 9 calories per gram = 765 calories



FitnessThe Writers