To understand what calories are and what is their role in the human body, we must start from the diet itself.
In our body, food is broken down by oxidation. We can even say that the food is “burned”. Warmth which is released during combustion is measured in calories. Gram – calorie is the amount of heat needed to keep the temperature of one gram of water by one degree raise. Kilogram – calories, or just calories, are thousand times higher measure, and measuring of calories of combusted food is usually taken in kilo – calories.
Each type of food, while it burns, releases a certain number of calories. For example, one gram of protein provides four and one gram of fat provides nine calories. In the human body it does not matter which of these substances are burned, until the body gets enough energy to sustain life.
The number of calories body needs, depends on the work it performs. Man weigh about 85 kg need only 1,680 calories a day when completely in idle state. If such a difficult man performs an easier job, he needs 3,360 calories a day, and to perform strenuous work he needs 6,720 calories to keep the body in those conditions normally.
Children need more calories than adults, because except for work, they are still growing. We need more calories in winter, than in summer. “Fuel” that our body normally uses is the starch and sugar. What happens if we take more of these substances than we need? Body consumes only as much as it needs and keeps certain stocks for later. Such stock will be approximately one-third of the quantity needed for one day. Everything else is converted into fat.