What Are Calories?

Calories are a unit of energy used by the human body to provide energy. 

Two main definitions exist:

  • Calorie - A small unit of calories defined by the gram. It is the amount of energy needed to raise the temperature of one gram of water by one degree Celsius at one pressure of the atmosphere.
  • Kilo Calorie - A large unit of calories defined by the kilo. 1 kcal is the equivalent to 1,000 calories.

Calories work to provide your body with the energy it needs to perform day to day tasks ranging from maintaining homeostasis and survival to walking and working out in the gym.

Calories are used for everything from sprinting up a flight of stairs to ensuring your heart continues beating and your brain continues thinking.

The more you eat the more you calorie (energy) input is increased and the more active you are the more your calorie (energy) output is increased to fuel this activity.

If your calorie input is higher than its output you will gain weight and if your input is lower than your output you will lose weight.

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Useful Resources

MyFitnessPal - surely the most popular and wellknown calorie tracking food diary app

Calculating Calorie & Macronutrient Needs For Strength Training via

How to Count Calories Correctly for Effortless Weight Loss via 

Yes. It’s Not as Simple as Calories in Calories out but Calories Still Count. Here’s Why. via