What is a calorie in food?
This discussion gives you some insight into what a calorie in food is, the potential energy of food, the relationship between a kcal and a joul, and combusting values of foods in the human body and a bomb calorimeter.
In our everyday lives, the supplement and/or food we eat includes either macronutrients (carbs, fat and protein) or micronutrients (vitamins and minerals) or both groups at the same time. And it’s the only macronutrient part of our food which produces energy into the body.
Food is a rich source of energy. It’s the chemical bonds within our food that contain this energy. After breaking these bonds by the human digestive system, the body has access to the food’s potential energy. So the potential energy is the energy stored within a physical system.
Joul and Calorie – unites of measure for energy
In our daily lives But the standard unit of measure for potential energy is the joule or kilo-joule (1000 jouls). One Calorie is equivalent to 4.18 joules.
A Calorie is the amount of energy that increases the temperature of a kilogram of water by one degree centigrade. There is some confusion with the use of the term, as there are small calories (cal) and large calories (Cal or kcal). Indeed, 1 Cal and/or kcal is equal to 1000 calories (cals).
Combusting food in a Bomb Calorimeter and physiological values
Interestingly, food contains slightly different amounts of energy in the body and bomb calorimeter. By combusting or burning the food under standardised conditions, we measure energy in food. This combustion can take place in a bomb calorimeter. A bomb calorimeter is the most common device for measuring the heat of combustion or calorific value of a material. To clarify, the number of Calories of food In the bomb calorimeter are:
- Fat (1 gram) = 9.44 kcal
- Protein (1 gram) = 5.65 kcal
- Alcohol (1 gram) = 7.09 kcal
- Starch (1 gram) = 4.18 kcal
- Sucrose (1 gram) = 3.94 kcal
- Glucose (1 gram) = 3.94 kcal
While, in the human body, carbohydrates and protein contain 4 kcal per gram, fat 9 Cals per gram and alcohol 7 kcal per gram. These are physiological values. Physiological values are the numbers obtained inside the body, not outside the body.
Surely, the discussion above has given you some insight into what a calorie in food is. We’d love to hear from you and you can comment below for asking any question.
The Bottom Line
What is a calorie in food?
A Calorie is the amount of energy needed to increase the temperature of a kilogram of water by one degree centigrade. Food is a rich source of energy. It’s the chemical bonds within our food that contain this energy. After breaking these bonds by the human digestive system, the body has access to the food’s potential energy.