How to Calculate Energy Content of a Food Product
Determining the energy content of food products depend on:
1) the nutrient components of food which provide energy (fat, protein, carbohydrate, alcohol (ethanol), organic acids and dietary fiber compounds);
2) the quantity of each individual component must be converted to energy content which calculated using specific factors;
3) the energy contents of all components must be summed up together to represent the nutritional energy value of the food for humans.
The energy conversion factors and the models currently used presume that each component of a food has an energy factor that is fixed and that does not differ according to the proportions of other components in the food.
The procedure for calculating the energy content of a food product as following table:
|
Nutrient |
Amount |
Multiplied by |
Equals to |
| Fat |
______ g |
9 kcal |
=______ kcal |
| Protein |
______ g |
4kcal |
=______ kcal |
| Carbohydrate |
______ g |
4kcal |
=______ kcal |
| Alcohol (ethanol) |
______ g |
7kcal |
=______ kcal |
| Organic acids |
______ g |
3kcal |
=______ kcal |
| Dietary fiber |
______ g |
2kcal |
=______ kcal |
| Energy content of the food (summed up) |
=______ kcal |
||
Example of How to Calculate Energy Content of a Food Product
Product A comes in a 1 liter package and the recommend number of serving is 4 (one serving =0.25liter). The package contains 113.2g carbohydrate, 21.9g fat, 30.6g protein and 1.4d dietary fiber.
How much kcal energy does one serving of product A provide?
| Energy from carbohydrate | : | 113.2g x 4 kcal | = | 452.8 kcal |
| Energy from fat | : | 21.9g x 9 kcal | = | 197.1 kcal |
| Energy from protein | : | 30.6g x 4 kcal | = | 122.4 kcal |
| Energy from dietary fiber | : | 1.4g x 2 kcal | = | 2.8 kcal |
| Energy per package | : | 452.8+ 197.1+ 122.4+ 2.8 | = | 775.1 kcal |
| Energy per 100ml | = | 775.1 x 100/1000 | = | 78 kcal or 324 kJ |
| Energy per serving (250ml) | = | 775.1 x 250/1000 | = | 194 kcal or 811 kJ |
*remark: 1 kcal= 4.184kJ
