What is a Calorie? - Coach Mikki

What is a calorie?
Let me firstly state, that I hope many people reading this have a base overview of nutrition. If not, we will be exploiting some of the Instagram and Facebook posts you may have read out in the open.

Energy balance, a key in modulating your body weight and body composition. Simply put this is calories in vs calories out, the amount of food your eating (energy in) versus the amount of movement and exercise you’re doing (energy out). This is why I push so many of my clients to monitor their steps, cardio and training. The more variables we can track the more data we can obtain, the more we can manage and the better the results will be. This being said, long term consistency is going to make for more accurate results, but let’s not get off track here.

The energy balance equation was created to represent what should happen to the body when looking at the difference between energy intake (from food) and energy output.

Energy in = Energy out + Change in Body Stores


Without getting super sciency and boring on you, changes in body stores will show up as changes in different tissues (fat and muscle). Excess energy is converted or stored via conversion into body tissue and vice versa if energy intake is less than output, the body will utilise stored energy and there will be some loss of tissue. I hope you’re still following me.

Energy in is accumulated from the calories consumed from carbohydrates, proteins, fats, fibre and alcohol. If you have read up on our “How To Flexible Diet” you would have an understanding as to how to track these. All of which are burnt off/digested at a slightly different rate and efficiency.

Energy out consists of 4 aspects to the equation, Resting/Basal Metabolic Rate (RMR/BMR), the Thermic Effect of Food (TEF), the Thermic Effect of Activity (TEA) and a more recent addition which is Non-Exercise Activity Thermogenesis (NEAT). I won’t dive too deep into these as I hope the names in itself clarify what they are. But TEA is energy burnt through direct exercise completed at the gym etc. and NEAT is energy burnt throughout your day to day living.

Just one final touch on the equation, it is forever changing, when it comes to weight loss and gain. When you are in a caloric deficit generally your RMR/BMR drops considerably. Due to the fact you’re eating less food and dropping weight your TEF is automatically reduced. You add in additional cardio (TEA) to counter this however throughout the remainder of the day at work or home you’re moving less (NEAT). We need to monitor all these objectives and some, to ensure the changes in your body tissues are as per the client's goals, (reducing fat, gaining muscle). All of which takes time and planning.


So, tuning more into why you clicked onto this article. Calorie is a unit of measurement. More specifically  calorie values of food are nothing but a representation of the heat energy given off when they are burned.

Now this wouldn’t be a fair article if I didn’t discuss why some people do not believe in the calories in vs calories out argument. Many opposing scientists state that our body is not a calorie burning furnace. Which is true, as stated earlier our body absorbs each macronutrient at a slightly different rate and not all is consumed, exiting through your stool.
Foods are also metabolised within the body and some of the energy may be lost in this metabolism, this is the Thermic Effect of Food. Simply put, 4 calories of protein won’t be 4 calories in the body due to the changes in digestion and absorption.

Calories, like other concepts such as watts or horsepower, are a acceptable representative for something that does exist.


Now after reading all of this some of you may be thinking, well shit. I want to lose some body fat why don’t I just jack my total consumed calories way down and introduce some additional cardio to lose the excess weight. This is a fast track to disaster. How many stories have you heard where you join a 10 week challenge, drop a tonne of weight and within 12 months the weight has been reintroduced?

It’s easy to sit back and talk about the sciences behind it all, you need to make it applicable to your lifestyle. The situation noted above does not address the reason why you got fat in the first place. “Slow and steady wins the race” this also applies to nutrition.

“The body’s response is to down-regulate the amount of energy it needs by lowering thyroid (t3).  T3 activates mitochondria in your muscle cells and organs to burn nutrients. T4 is the inactive form of thyroid and is the majority of what your thyroid produces.  You rely on liver and kidney enzymes to convert T4 to T3, but if your body is over-stressed from dieting, excess cortisol can suppress thyroid stimulating hormone and decrease thyroid function.

The two most disruptive changes to thyroid levels are first, reducing calories too low and second, reducing carbohydrates too low. ”
- Tony Gentilcore https://tonygentilcore.com/2014/03/recovering-metabolism-need-increase-decrease-calories-part/

We eat food, which contains nutrients and when metabolized by the body we create energy which can be translated into heat which can be measured in calories.  Calories are simply a proxy for the food/nutrients in the diet.