kilokaloria

Kilokaloria, abbreviated kcal, is a unit of energy used primarily in nutrition to express the energy content of foods and beverages. One kilocalorie equals 1000 small calories (cal) and is equal to 4.184 kilojoules (or 4184 joules). In many contexts, especially in English-language nutrition labeling, the term calorie is colloquially used to mean kilocalorie.

Distinctions and terminology: The small calorie is a unit used in physics and chemistry, while the kilocalorie is the energy unit commonly used to quantify dietary energy. On many nutrition labels, energy is listed as calories or kilocalories; in scientific writing, kcal is preferred to avoid confusion with the smaller unit.

Macronutrient energy values: Carbohydrates and proteins provide about 4 kcal per gram, fats about 9 kcal per gram, and alcohol about 7 kcal per gram. These values are averages and can vary depending on food structure and digestibility. The energy content of foods is usually measured by bomb calorimetry or estimated from nutrient composition; the metabolizable energy available to the body can differ due to digestive efficiency and individual metabolism.

Usage and context: Kilocalories are widely used in dietary guidelines, meal planning, and food labeling. While the kilocalorie remains common in many countries, the related unit kilojoule (kJ) is the SI unit for energy, and many labels provide both units. Understanding kcal helps compare the energy provided by different foods and manage energy balance for health and nutrition.