Calories is a unit of measuring thermal energy defined as the amount of heat needed to raise the temperature of one gram of water by one degree centigrade. (Between 5 and 14 ° C and 5 and 15 ° C) under regular atmospheric pressure (1 atmospheric pressure or an equivalent of 101.325 kPa). It is a unit to measure the thermal energy needed and created by the body in order to carry out its work normally, by burning food. A person needs the energy to carry out his basic functions of life, and this energy is primarily from food and oxygen that we breathe. The food differs in the amount of energy it produces on what it contains from the three basic elements in the food, namely: carbohydrates, proteins, and fats

The use

The word “calorie” means in English (1 cal) and this is not completely correct because that calorie is what is sometimes called a “small calorie”; In the field of nutrition when talking about calorie, we usually mean “big calories”; It is in English (1 kcal) 1 kcal; That’s 1,000 small calorie.

In the field of nutrition, where the list of contents is written on the canned or bag (let it be a bag of rice, sugar or lentils), both formulas are sometimes used, and in most cases it means a large price (1 kcal).

Sources of calories

These sources produce thermal energy in varying proportions:

Carbohydrates: produce 400 calories (100 grams) per 100 grams. In English, one kilogram of calories is one thousand calorie.
Fat: produces about 900 calories per 100 grams; That is 900 kilocalorie per 100 grams.
Proteins: produce 400 (large) calorie per 100 grams; That is, 400 kcal / 100 g protein.
That is why it is necessary to distinguish between the price and the large price which is 1000 calories (small).


Calories are found in vegetables and fruits in small amounts relative to carbohydrates; While we find in carbohydrates 400 large calorie / 100 grams, they are for vegetables between 20 – 40 large calories / 100 grams. Eating salad from fresh vegetables before eating, for example, helps reduce carbohydrate, fat and meat intake, so people feel full and have eaten adequate quantities of carbohydrates, proteins, fats and vegetables, so they do not lead to weight gain that we do not want.

For eating vegetables and fruits, nutritionists advise that they contain all colors as possible: such as yellow or red carrots, red tomatoes, red bell peppers, yellow bell peppers, green radishes, green cucumbers. Fruits: strawberries, red apples, yellow apricots, yellow guava, blueberries, red grapes and their equivalents, bearing in mind that a week does not pass without eating three or four types of this assortment. The body’s organs perform their functions and improve their immunity against epidemics and diseases. The purpose of persevering in eating those healthy foods rich in vitamins and minerals (calcium, magnesium, iron, phosphorus, iodine, etc.) is for the body to obtain its needs and not lack any element, so that it remains healthy and healthy.

Body needed

The body needs a specific amount of calories daily, and it increases according to the person’s activity, the size of his body, and age. Children and young adults in the process of developing need large amounts of calories. There must be a balance between the calories we take from food and the calories we burn so that our weight does not increase because the body stores the extra calories it needs in the form of fats to use later if it is forced to do so in the event of a decrease in calories taken by eating. If we eat too much, the amount of fats increases. If we reduce food, the body uses fat to produce energy and burn it, so our fat decreases.

The body consumes calories from food in all its vital activities such as breathing and digestion and the work of all devices such as the heart, kidneys, liver, as well as thinking.
The body also consumes calories during its physical activity, such as walking, running, climbing the ladder, carrying weight, and sports.

Definition of calories

The energy needed to increase the temperature of a given block of water by 1 ° C depends on the temperature. Therefore, in the table below we find different (but close) values ​​that were measured at different temperatures. Such as at 0 ° C, at 15 ° C, or at 20 ° C. The most common definition, and in particular the price used for food, is the measured price at 15 ° C.

The calorie conversion factor for joules is:


1 calorie (small) = 18 and 4 joules.
There are two calories names:

Small calorie, which is the calorie per gram of water, and symbolized by cal. It is the amount of heat needed to raise the temperature of 1 gram of water by 1 ° C, which is approximately 2 and 4 joules.
The large calorie, or calorie per kilogram of water, which is known as the calorie of food, symbolized by the symbol Cal or kcal.
This is the amount of heat needed to raise 1 kg of water by 1 ° C. It is thus 1000 times more than the small calorie, and accordingly the amount of the large calorie is 2 and 4 kilojoules

Calories and energy balance

Energy balance We mean by here is the amount of energy entering the body in the form of calories from different foods, and the amount of energy that comes out of it “consumed” through various daily and vital activities.
And this balance is the secret of losing or increasing weight if we know how to control it in order to reverse the equation in favor of what we want to achieve. It is as follows:

1_ If the equation is as follows: the energy entering the body = the energy consumed or leaving the body, then this means maintaining a constant weight.

2_ The following equation: The energy entering the body> of the energy consumed, then this means extra calorie in the body, which may mean converting and storing it in the form of fats in the body, and thus increasing the weight if this system is adopted as a way of life.

3_ If the equation is as follows: the energy entering the body <of the energy consumed, here we get the results of weight loss and loss of accumulated fat in the body, and this is what most certainly hope for!


Calories in different foods

Knowing the caloric intake in foods eaten daily is very important for maintaining a healthy weight and making sure that we do not start more than necessary.

It is possible to determine the amount of calorie in packed and processed foods via the food label, which shows the amount of energy under the name “calories”, and by using a unit of calorimetry or calories.

To find out more about the food label and how to read it, just enter the following article: Food labels are a way for us to feed healthy.

As for the calorie contained in different foodstuffs, this is specified in the menus and their alternatives according to the food rations of the different groups. For example: a grain of medium-sized fruits such as a small apple, which is equal to one food ration of fruit rations, it provides us with approximately 60 calories, while A portion of starches such as bread, which is equal to 30 grams, provides us with approximately 80 calories and so on.

To find out more about the food rations and their quantities, here is the guide for determining the amount of rations: The guide for determining the amount of food and rations.

Calories consumed

The amount of calories a person consumes by performing a specific physical activity varies depending on a group of factors, including size, age, intensity and type of activity. The more you perform the activity with more power and effort, the more calories you burn.

For example, brisk walking consumes more calorie than walking at a moderate pace. We should not forget to mention that the human body consumes more calories to carry out the necessary metabolism, and its various vital functions are respiration, digestion, brain functions, and others.