kilocaloría

A kilocalorie, often abbreviated as kcal or Calorie (with a capital C), is a unit of energy. It is equivalent to 1,000 calories. In common usage, particularly in nutrition and dietetics, the term "Calorie" (uppercase C) refers to a kilocalorie. This unit is used to measure the energy content of food and the energy expenditure of the human body.

The kilocalorie is defined as the amount of heat required to raise the temperature of one kilogram of water by one degree Celsius. While the calorie itself is a metric unit, the kilocalorie is more frequently encountered in practical applications. The international joule (J) is the SI unit of energy, and one kilocalorie is approximately equal to 4.184 kilojoules (kJ).

In the context of food labeling, the energy provided by carbohydrates, proteins, and fats is typically expressed in kilocalories. For instance, 1 gram of carbohydrate provides about 4 kcal, 1 gram of protein provides about 4 kcal, and 1 gram of fat provides about 9 kcal. Understanding kilocalories is fundamental for managing dietary intake and energy balance.