Nutritional definition: a calorie is a unit of energy required to raise the temperature of 1 kilogram of water by 1°C (33.8°F). It is referred as large Calorie with capital C (Cal), or kilocalorie (kcal). One Cal is equal to 4.184 kilojoules. This website refers to the nutritional definition of calories. Calories (energy) from food are used for growth, development and functioning of our bodies.
Chemical definition: a calorie is a unit of energy required to raise the temperature of 1 gram of water by 1°C (33.8°F) at a pressure of 1 atmosphere. It is also referred to as small calorie (cal).
The relationship between the two definitions is: 4.184 kilojoules = 4,184 joules = 1 Calorie = 1 kilocalorie = 1,000 calories
By adding up the amounts of energy producing components (carbohydrate, protein, fat and alcohol) it is possible to measure the energy in food.
|Energy components||Cal||kJ||Special notes|
|Alcohol||7||29||Energy-dense. Alcohol is not really a nutrient as it is not essential for survival. However, it is a substance required for calculating energy.|
|Carbohydrates (Net)||4||16||Total carbohydrates – Dietary Fiber.|
|Protein||4||17||Relatively inefficient source of energy and is better utilized for growth and support of body functions.|
|Dietary fiber||2||8||The most accurate figure due to the latest research. (read more..)|