The Differences Between Calories and Kilocalories

Ingesting more calories than necessary can promote the appearance of fatty tissue, capable of negatively influencing a person's state of health.
The Differences Between Calories and Kilocalories
Saúl Sánchez

Written and verified by el nutricionista Saúl Sánchez.

Last update: 29 March, 2021

Calories and kilocalories are ways of measuring the caloric content of a certain food. Although they’re usually used to name the same concept, the truth is that they represent different values. We’ll explain everything to you below to clear up any misconceptions you may have.

Keep in mind that maintaining energy balance is essential in the context of a healthy diet. In this way, fat weight gain is prevented, which is related to an increase in inflammation and a worsening state of health. Maintaining a good body composition is crucial.

Calories and kilocalories are not the same

A calorie is a unit of thermal energy that refers to the amount of heat it takes to raise the temperature of 1 gram of water by one degree Celsius. A kilocalorie, on the other hand, expresses the same concept, but its measure is greater – it’s equivalent to 1000 calories.

However, the term calorie is commonly used to describe the kilocalories found in the foods that we consume in the diet. However, this could create some errors. In any case, and despite the fact that the name is used incorrectly, the idea that it’s intended to convey is closely related to health.

The importance of energy balance

For some years, people promoted the idea that successful diets were the ones that were based around counting calories. This method is known as “CICO” and presupposes the idea that if you expend the same amount of energy as you ingested, then your weight should remain unchanged. However, there are several other factors that also come into play, and we’ll explain them to you now.

What’s clear here is that avoiding fat weight gains is essential in order to maintain overall good health. According to a study published in the journal Circulation Research, obesity and being overweight are factors that can increase the risk of developing cardiovascular diseases.

This is because, among other things, they promote cascades of inflammatory substances. This can create a deficient functioning in many organs, which ends up causing illnesses.

There’s life beyond calories

Many diets focus only on caloric balance, and the need to generate an energy deficit in order to promote weight loss. However, there are other factors that determine the reduction of adipose tissue as well.

Among them, we can mention metabolic health. If there isn’t a correct use of nutrients, then it’s possible that unwanted accumulations will occur.

This situation can occur when a person develops insulin resistance. The regular consumption of simple sugars has been shown to predispose a person to this condition.

From here on, the person’s metabolic flexibility and the ability to oxidize fats to generate energy are reduced, and so the person tends to accumulate them.

Other factors can also have a decisive influence on weight loss, such as sleep quality. For example, sleeping for a few hours is associated with a higher basal energy consumption, but also with an increase in appetite, which leads to eating more food. This is evidenced by research published in the journal Obesity Reviews.

Don’t count calories to lose weight

Although it’s important to have an approximate idea of the calories that you ingest through your diet, this factor isn’t essential in order to control weight loss.

It’s much more effective to promote healthy lifestyle habits, among which are a good diet, regular physical exercise, and proper rest.

The diet

From a dietary point of view, it’s necessary to reduce the consumption of ultra-processed foods. Not only are they the foods that have the most calories, but they also have additives and unhealthy trans fats. The latter have been shown to be favor inflammation, which is associated with an increased risk of illness.

At the same time, you need to guarantee a high consumption of vegetables. These have dietary fiber, a substance capable of increasing satiety, according to current evidence. At the same time, they have antioxidant phytonutrients in their composition.

Phytonutrients regulate inflammatory states and neutralize the formation of free radicals, thus preventing the development of chronic pathologies in the medium and long term.

Finally, it should be noted that it’s necessary to consume water in optimal quantities, around 2.5 liters on a daily basis. Juices, soft drinks, or alcoholic beverages shouldn’t be ingested.

This type of product increases insulin resistance due to its content of simple sugars. In addition, they alter the intestinal microbiota and provide empty calories, with hardly any nutrients, and even alter cognitive performance in the short term.

Physical exercise

To maintain a correct state of body composition, physical activity is essential. Exercise is the perfect complement to the diet, as it improves the body’s efficiency in obtaining nutrients.

In this way, insulin resistance is reduced and metabolic flexibility is increased. In addition, sports practice is able to ensure that inflammation remains in optimal ranges.

Exercise is very important to eliminate excess calories.
Consistent exercise makes it easy to eliminate calories.

According to research published in the journal Obesity Reviews, high-intensity interval exercise is the most effective way to generate improvements in body composition. Not only does it allow you to burn a high number of calories while you do it, but the metabolism remains activated some time after you finish the activity.

It should be noted that this modality is also capable of generating muscle hypertrophy, this being a metabolically much more active tissue than fat.

However, strength work must always be alternated with aerobic exercise. In this way, it will be possible to increase your heart efficiency, allowing it to pump blood adequately to all tissues.

If you generate a large decompensation between muscle mass and cardiac power, then complications could develop in the medium term. All body systems must act in a coordinated way.


The last of the factors that determine the state of health and body composition is rest. During sleep, many processes take place in the body that help it to recover from the stresses and exertions of the day.

Hormones such as GH are released that allow the growth of tissues and the reduction of muscle catabolism. In addition, its a period during which inflammatory processes are regulated, thus improving the state of health.

The combination of adequate mental and physical hygiene will allow you to have a good state of health.
Mental hygiene also favors an adequate energy balance.

Alterations in the quality or duration of sleep can condition the human body’s ability to use the calories ingested. They can also promote states of depression or anxiety, which will lead the subject to eat more food than necessary, altering the diet.

For this reason, it’s crucial to ensure good sleep hygiene, based on the acquisition of correct habits. The latter include the following:

  • Avoid using devices for a bit before going to bed
  • Take supplements with melatonin
  • Avoid large meals at dinner time

Please note that calorie counting is an imprecise method

If, despite taking care of all the aspects that we’ve discussed, you still feel safer counting calories, then keep in mind that this mechanism has certain inaccuracies. When estimating calories ingested and consumed there’s a wide margin of error, as it’s only an estimate.

Body composition, sex, age, and type of activity are factors that can influence the calories consumed throughout the day.

Although there are formulas that can provide an approximation, it will often be necessary to correct it as you find the balance. If your aim is to lose weight, then it may also be necessary to modify the dietary pattern that you were following.

In general, we can affirm that the protocols that are based around intermittent fasting usually efficiently generate a caloric deficit. This is because they tend to omit at least one meal throughout the day.

If the calories that aren’t consumed aren’t compensated, then the balance will shift in favor of using up the calories. From here, you’ll begin to experience weight loss.

Calories and kilocalories, often the subject of criticism

A large number of diets focus on reducing calories. However, as we’ve seen, there are other factors that condition weight loss or that help to maintain good health. For this reason, we recommend that you don’t get too obsessed with this parameter, as in some cases it can lead to error.

It’s clear that to promote a good body composition it’s necessary to create a balance between the three aforementioned pillars: diet, physical exercise, and rest. If all of them are taken care of, it will be possible to guarantee an ideal weight in the medium term. However, if one of them fails, then the balance could be truncated and stagnation may occur.

Remember that if you have doubts about how to properly prepare your diet, then you can always go to a nutritionist. This will be able to estimate the calories you use and the ones you need, in order to develop a consistent dietary guideline. You simply have to put it into practice and experience improvement over time.

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