A guide to calculate calories

As a method of introduction for the first part and the Foundation of our dietary structure, we need to talk about the only immutable element.

For those of us who pursue goals of body composition, it is essential to understand the law that governs the constant process that we go through every day known as Energy Balance. Fortunately it’s simple and we can define it as: [Energy in – Energy out = Energy Balance].

On one hand we have the energy in which is the easiest to define, since it has a single source which is our food. The most difficult to assess is the energy out, which we’ll focus on first on this article to individually define how many calories in average we burn daily. That way we can establish a good model that allows us to calculate our Energy Balance and predict a possible outcome for our diet.

Energy Out is important to be determined to be able to know how much you should eat to achieve your goal, in this article you can read in more details where the Total Daily Energy Expenditure comes from, here I want to put in practical terms how to calculate your daily calories and adjust your calorie consumption to keep the rate of weight gain/loss you’ve decided.

What is a Calorie?

For the purposes of our diet, Calorie is the unit used to measure the energy value that we use to carry out our daily bodily functions. As I mentioned before, food has an energy value and we have an average daily energy expenditure, so we can use this unit to give the appropriate values to both sides of the equation.

Calories in food vary depending on their content in macronutrients, and calories we spend depends on several factors, first let’s talk about the method to determine our energy expenditure.

Fun fact about calories before you get bored of me, you have probably seen the terms: Kcal, cal, Cal, and how people use them interchangeably.

I’ll be the first one to admit that it really doesn’t matter much, but my inner nerd (innerd? See, I got dad jokes too) kicked in and I have to explain it, really quick I promise.

The difference lies in lower case “c” in calories, and capital “C” in Calories. So, the lower case refers to the basic unit of energy, whereas the capital means 1000 of them. And Kcal is short for kilo-calories, where kilo means 1000.

A calorie is the amount of energy needed to raise the temperature of 1 gram of water by 1ºC, where a Calorie (or Kcal) is the amount needed to raise the same temperature on a kilogram of water.

A Kcal is also what we use to measure the energy in our food.

This is often ignored (except in technical papers) and people simply use whatever they want, I do it all the time and you can probably see it in this same post, only when putting it next to a number will I use the Kcal.

Now you have another useless fact to tell in a meeting when there’s an awkward silence, not that it will help the awkwardness and make you look cool but at least you have something to say. You are welcome!

Energy Out

For starters I want to make it clear that the number we calculate with any method will always be an estimate and nothing more, eventually we will be able to determine our individual energy expenditure more accurately.

The most influential factor is the person’s weight followed by physical activity, so you are going to use your weight in kilograms, multiply it by 22 (for my imperial system users, multiply your weight in pounds by 10) and the result will be multiplied by a factor depending on your physical activity:

Using this method and with the intention of making this guide relatively practical we can then use the following formula:

(Weight in kg) * 22 * (multiplier of physical activity)  or  (Weight in lbs) * 10 * (multiplier of physical activity)

Let’s use my weight at a point of 85Kg (187lbs) as a reference and with a light activity of 1.35:

85 * 22 * 1.35 = 2525  or   187 * 10 * 1.35 = 2525

This means that ~2500Kcal is my daily energy expenditure, aka maintenance. This gives me a base on which I can choose my goals since it gives me an approximate caloric perspective to work a surplus (if I want to gain weight) or a deficit (if I want to lose weight) .

It is important to mention that this method tends to overestimate calories in obese people and underestimate it in leaner individuals. In the same way it overestimates it in older people, the older we are the less calories we burn, although it’s not something very noticeable unless you compare a 20 year old with someone who is 80.

In any case this method works for most of my potential readers, and because it’s just an estimate it should be modified depending on the results in tracking measurements through time, and we’ll talk about this later. Remember that this is nothing more than a starting point.

Energy in

This is the part of our equation that causes the most confusion for a lot of people, despite being simple in physical terms. Part of the confusion is that some people are not aware of how many calories can have a given food, and others don’t even know if something has calories or not, it’s a common thing to see a disappointment face when I tell one of these people that the milk or cream that they use in their coffee contains calories.

It’s healthy!

Another reason that causes confusion is the idea that something is “healthy”, and while we could argue how healthy some food might be, it’s indisputable that they contain calories, and for the simple fact of having beneficial properties, doesn’t mean that they are low calorie. Spinach and almonds are both considered to be healthy, but their caloric content are extremely opposite:

Therefore, many people think that eating “healthy” foods automatically results in weight loss, when in fact as we all know it’s calorie restriction that causes you to lose weight.

For this reason it is essential to create an awareness of the calories in the foods that we eat on a daily basis, this will make us notice the amount we actually eat, as well as learning what are the best options that we have to avoid calorie over-consumption.

Hidden calories

Counting the calories in our foods is the first step to begin controlling our consumption and be able to handle our objectives in an efficient way. The impact that many of the ingredients and seasonings that are used for cooking have is another element that is masked for many people. Oils, dressings, and other additives increase the caloric value of what we eat, without knowing how much they contribute to our total daily intake, we could be consuming more than we know.

Imagine a typical salad of lettuce, tomato, cucumber, celery, chicken, and to add some flavor you pour some dressing. All the ingredients except the dressing, in proportions for a single salad, can add some 120Kcal, and then the sauce can duplicate or to triple this amount. Consider that:

With this perspective it’s easy to see how a little of something can add a significant amount of calories, in part this is because most dressings are oil based, which are calorically dense. There are many alternatives for dressings that are relatively low calorie and still provide good flavor, as with most things the trick is to be smart with our choices.

Drinks are frequently another source of calories that mysteriously slip up in our daily intake because we either don’t know or we’re not aware of the value they contain. Soft drinks, fruit juices, sugary drinks, milk, and others. A Starbucks coffee can contain up to 700Kcal for example, however a lot of people are unaware that these beverages contain calories.

Identifying content 

The question that follows is: How do we then know the calorie content for each one of the foods that we eat? Fortunately, the vast majority of what we buy contains nutritional information with details that include the calories. In other foods such as vegetables, fruits and others, there are lots of websites that have a great database to search the nutritional information of any food.

There are also popular applications like myfitnesspal, and pages like CalorieKing that make this search easy, and you can even record and monitor your daily intake in some of these. This is an individual task, because it’s something that you have to look for depending on your preferences, and learn to recognize what are the best options according to your requirements.

What’s left now is, depending on the objective, decide how much to increase or decrease in our daily consumption.

Finishing the equation

Now that you have your estimated energy expenditure, and an idea of what you should eat, the next thing is to put it into practice in a 21 day protocol I like to use.

Energy In: Continue to eat what you normally would, but using the tools to find calories in what you eat start a diary where you record everything you consume, for three weeks you will do your very best to record what you eat as accurately as possible in its calorie content. At the end you should have 21 days of calories consumed, add them all and divide it by 21

Energy out: At the same time on this side you will be weighing yourself every one of those 21 days. To do this efficiently it is highly important to weigh yourself everyday under the same conditions. The best time of the day is when you wake up, after using the bathroom, before drinking or eating anything and naked. The reason is that bodyweight fluctuates considerably during the day due to hydration and the food we eat. So simply record your weight every morning, and at the end of the week you can find an average by adding the weight of every day and dividing it by 7. This is a week in my personal history:

After the 3 weeks we can compare the weights and see more objectively if we lost, maintained, or increased weight. Continuing with my history, here are 3 weeks of average weights.

In this case I was losing weight, in these 3 weeks I lost 0.8Kg. If we remember that 1Kg of body fat has a value of ~7700Kcal and I lost 0.8Kg, it means I had a 6160Kcal deficit during those 3 weeks, so then if I divide 6160 / 21 days it will give me the daily deficit of 293Kcal.

Now, if my average calorie intake was of 2000Kcal and I had a calorie deficit of ~300Kcal, this shows that my average Energy Expenditure was of ~2300Kcal. My initial calculation with the previous formula (at 85Kg or 187lbs) gave me an estimated Maintenance of ~2500Kcal (85*22*1.35 = 2525 or 187*10*1.35 = 2525). I wasn’t so far from my real Energy Expenditure.

Nerd note: this example reflects something interesting happening in hypocaloric diets, the reduction of energy expenditure mainly from spontaneous activity and energy in general. There is that inevitable drowsiness that we experience when we spend time eating below our maintenance, and as you can see it has a considerable impact. 

An average of 10% reduction due to these mechanisms is what is found in the literature, and anecdotally I can attest that it is true, especially when we consider the calculations in the example above, where it shows that approximately 10% of reduction in what was expected originally.

In summary:

This means that empirically my Energy Expenditure under the conditions in which I was (nutrition and physical activity) was of ~2300Kcal. This is a more accurate and educated calculation to manipulate my nutrition and/or physical activity towards the objectives that I want, so depending on which goal that is I can adjust by increasing if I want to maintain or bulk up, or reducing if I want to lose weight.

As a final note, I want to say that our Maintenance is always going to be slightly variable, depending on our physical activity mainly and affected by other minor factors but that in the whole may modify it.

However, it won’t be that far from the one we calculated with the real metrics, and there’s no need to worry about monitoring it constantly, only if you make a notable change in physical activity (switch from a desk job to another physically demanding for example).

More than anything, this practice creates an individual perspective of what our calorie expenditure is, and it helps us maintain an idea of what we should consume.

Thanks for reading, questions are always welcomed in the comments.

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