How to calculate the calories you need: understanding what you need to maintain, gain or lose weight

Ideally we come to a place where we know enough about food, nutrition, food portions and our own bodies where we can practice mindful eating and not count calories while maintaining a healthy weight. This doesn’t take long to learn but for some people who have never thought about it and who are looking to lose, maintain or gain weight, learning about calories can be a helpful thing especially in the beginning of a program to reach their goals. 

There is so much talk about calories but do you really know what “calories” means and how we find out how many calories our bodies should take in from food? It can be hard to wade through the massive amount of information available to be found on diets, nutrition, health and fitness to find out exactly what you need to actually know, understand and implement.

So,  you’re in the right place to get some thorough but simple and clear information about calories! 

First, what are “calories”? 

The scientific definition of a calorie is: the amount of heat energy needed to raise the temperature of one gram of water by one degree Celsius.

A calorie is actually a unit of measurement, not actually a “thing”.

A calorie measures the amount of energy in the food and beverages that we consume. We need this energy from food to live and stay healthy. Everything our bodies do relies on the energy that comes in the form of calories.

So how do calories work in our bodies. Calories in food provide energy in the form of heat so that our bodies can function. Our bodies store and burn calories as fuel.

Calories in food provide essential energy and we do need some stored fat to survive.

BUT - if we take in more calories than we need to function our bodies will gain weight over time. 

There is a baseline amount of calories you need to consume just to keep your body alive. 

Daily energy calorie needs are determined by 3 things:

> Basal Metabolic Rate (BMR):  (also sometimes referred to as Resting Metabolic Rate or RMR):  this is the amount of energy measured in calories expended by our bodies during quiet rest. BMR makes up for between 60-75% of the total calories used daily.

 > Thermogenesis: this is the amount of energy measured in calories needed by our bodies to digest and absorb the foods and nutrients we consume 

>Physical activity: this is the amount of energy measured in calories our body uses in daily activities. This is the number of calories needed that will vary the most as it depends on the frequency, intensity and duration of our various activities. You “burn” calories constantly, even while sleeping or sitting. You burn more when you are engaged in more physical activities. Regular physical activity is the best way to increase the number of calories you burn.

All three of these things make up what is called “Total Daily Energy Expenditure” (TDEE), which is a measure of how many calories we burn per day taking all these 3 things into account. 

So, our bodies are constantly using calories to provide the with the energy we need to not only do activities but also just to exist and survive. Calories are used to keep our hearts beating, our lungs breathing and our brains functioning.  Without sufficient calories, our bodies can’t function. 

To calculate a pretty close estimate of the number of calories you need just to maintain your body needs you can use one of the many free calculators online. Here’s one that is easy to follow:  

https://tdeecalculator.net

This gives you a pretty good ballpark for how many calories you need to maintain your weight at  your current level of physical activity. The thing is, it is physical activity that is the most variable thing in many people’s lives so calorie needs may need to be adjusted sometimes depending on your goals. 

If your goal is weight loss or gain, we really want to focus on how many calories you are burning versus how many you are taking in through food. This is where the phrase “calories in, calories out” comes in that I’m sure you’ve heard a lot. 

“ Calories in” means  all the food and beverages  you take in that have calories in it (everything but water or vitamins if you take those as supplements). 

“Calories out” means everything you do that uses energy, from simply being alive (heart beating, lungs breathing, digestion even while at rest or sleeping) to walking, talking, activities and exercise. 

The relationship between the input and output of calories dictates whether you gain, lose or maintain weight. For example:

• Calories In > Calories Out = Calorie Surplus & Weight Gain - If the number of calories you eat is greater than the amount of energy you use, you will have a surplus of calories and will gain weight. 

• Calories Out – Calories In = Calorie Balance & Weight Maintenance - If the number of calories you eat is the same as the amount of energy you use, you will achieve calorie balance and maintain your weight.

• Calories In < Calories Out = Calorie Deficit & Weight Loss - If the number of calories you eat is less than the amount of energy you use, you will have a deficit of calories and will lose weight.

Each and every day you are in one of these calorie states (surplus, balance or deficit) so you are either gaining, maintaining or losing weight.

Using a TDEE calculator can help give you a pretty close amount of the calories you should be taking in with your current age, weight, gender, height and level of physical activity. Be careful not to overestimate your level of physical activity when you use one of these calculators as this will then calculate a higher number of calories and you will eat more than you actually need so may gain weight over time. 

Counting calories isn’t something you have to do every day for the rest of your life. But it CAN be really helpful if you have no idea currently what your calorie intake is or if you haven’t been able to reach your goals even though you THINK you are eating the right amount.

Nutrition Spark!": Counting and tracking calories in the early steps of your weight loss journey can help you learn how to eat healthy portions and eat the healthy foods which also help you feel full!

I hope this was helpful! For more on counting calories and lots of information on the calorie count in foods and nutrition, check out my course on nutrition HERE!

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