Calorie is a unity that does not belong to International System of Units . Its function is to express the thermal energy , indicating the amount of hot which is needed, with normal pressure, to increase the temperature of 1 gram of H2O by 1 ° C (from 14.5 to 15.5 ° C).
At International system , the calorie should be replaced by the July (A calorie equals 4.1855 joules), although its use is preserved as it has become popular to express power energetic They own the food.
It is possible to differentiate between two specific classes of calories: calorie-gram (also known as small calorie ) is that heat energy that is necessary to rise in 1º celsius the temperature 1 gram of H2O; the calorie-kilogram (or large calorie ), on the other hand, is the heat energy required for the temperature of 1 kilogram of H20 to increase by 1º celsius. This distinction, however, has fallen into disuse in recent years.
Importance of calories
The notion of calorie is important to explain the functioning of the food process. Living things need energy to survive; this energy is obtained from the food . Food, therefore, is the most relevant energy source for living organisms.
The energy obtained from the nutrients found in food is converted into calories or, more precisely, into kilocalories (that is, in thousands of calories). The body uses calories in diseases, situations of stress and processes of metabolism .
The obsession with calories
The number of calories present in a food must be specified on its label. This quantity is responsible for informing which is the energetic value of food and it is very important both to maintain the ideal weight and figure, and to try to recover them. When making a dish, it is essential to know how to differentiate between the different types of ingredients, use the appropriate proportion of each and choose the best cooking mode.
Regardless of weight problems, many people have developed a kind of obsession regarding the caloric content of food. The main reason is that at present you have access to a lot of information about the effects of meals on health, as well as its relationship with certain chronic noncommunicable diseases, among which are diabetes, hypertension and cardiovascular disorders.
The understanding of properties Nutritional food is essential to direct our diet in a healthy direction and to make this become a lifestyle and not a simple passing practice. To understand each of the values indicated on the packages, bottles and wrappers it is very advisable to ask a nutritionist for help.
Many times, due to lack of information and tools to understand the value energy of food, these are judged wrongly and more calories than ingested are ingested. A clear example is to avoid eating a chocolate chip cookie and replace it with twenty cereals.
It is very important to know the distribution of the so-called macro nutrients in each food and the amount of calories per gram they provide: carbohydrates and proteins, 4; fats, 9; and alcohol, 7. To facilitate the comparison of the caloric content of various products, it is always calculated based on 100 grams of the food in question.
The more water a food contains, the less energy it provides; in the case of vegetables, for example, almost 95% of its weight is wet. On the contrary, products such as bread and nuts have a high energy value, given the small proportion of liquid present in its composition. Fats, on the other hand, are the nutrients that add the most calories; It is the case of oils, butter and margarine, among others.