caloría

Caloría is a unit of energy. Historically, it was defined as the amount of heat required to raise the temperature of one gram of water by one degree Celsius. This is often referred to as a "small calorie" or "gram calorie" (cal). However, in many contexts, especially in nutrition and dietetics, the term "Calorie" (with a capital C) or "kilocalorie" (kcal) is used. A kilocalorie is equal to 1,000 small calories. It represents the amount of heat needed to raise the temperature of one kilogram of water by one degree Celsius.

The concept of the calorie originated in the 19th century during the development of thermodynamics. It became a standard unit for measuring heat energy. In physics and chemistry, the joule is the SI unit of energy, and one calorie is equivalent to approximately 4.184 joules. Despite the dominance of the joule, the calorie and kilocalorie remain in common use, particularly for quantifying the energy content of food. The energy provided by food is essential for all metabolic processes in living organisms, and kilocalories are used to measure this nutritional energy. When people refer to the calories in food, they are almost always referring to kilocalories.