Meaning of Calories
What are Calories:
Calories (cal) are units of the amount of energy, either contained in a food or burned by doing some type of physical exercise.
The word calorie is formed by the Latin root hot, which expresses high temperatures and the suffix -ia indicating quality. In its etymological sense, a calorie is the unit of heat necessary to raise the temperature of 1 gram (gr), or its equivalent 1 centiliter (cl), by 1 degree centigrade (C °). This also applies in its biochemical and physical significance.
Calories represent a unit of measure for the energy that humans incorporate through food and drink. Calories indicate the amount of energy stored in the chemical bonds of what is ingested. Energy is released during digestion and stored in different molecules and cells. The stored energy will be released when the body needs it and is used in 3 ways:
10% helps digestion
20% serves as fuel for physical activities
70% basal metabolism
The basal metabolism covers all the basic and vital functions of organs and tissues of a human being at rest. According to this definition, depending on the basal metabolism of each individual, the amount of calories needed per day will decrease or increase.
Calories and kilocalories
Calories (cal) are the smallest unit of a kilocalorie (kcal) with 1 kilocalorie being 1000 calories. In biology these 2 terms were used as synonyms causing some confusion.
Keep in mind that very few foods have more than 1000 kilocalories, an apple, for example, has 52 kilocalories. Calories are commonly used to refer to kilocalories (kcal).
Calories and metabolism
The amount of enzymes, intestinal bacteria, and the length of the intestine can influence each individual's ability to extract energy from food. This is what is known as metabolism.
Basal metabolism is the amount of calories necessary for the body at rest to carry out its vital organic functions. Based on average weight, physical activity, and muscle mass, a basal metabolic rate of 2,000 calories for women and 2,500 calories for men is indicated.
Calories in the Nutrition Facts Table
In the Nutrition Facts tables, calories indicate the amount of energy contained in the food.
Food energy present in food may or may not be absorbed by the body. Therefore, the amount of calories in a food does not mean its use.
In addition, some foods require more energy to be digested, such as whole grains and more fibrous vegetables, which means that the amount of energy absorbed is less than other foods that require less energy to be digested.
This is in terms of energy, but the calories do not indicate the nutritional value of proteins and vitamins that these other foods contain, for example. That is why a diet based only on calories can lead to overweight or malnutrition.