What do kilocalories (kcal) indicate?

Did you know?

Have you ever wondered what kilocalories (kcal) indicate?

The question may seem trivial, but it is not, since we often find abbreviations on the products we consume every day without really bothering to find out what they mean.
Kilocalories are in fact shown on all food packaging, supplements included.

The abbreviation kcal indicates the unit of measurement of the energy provided by a food.
One kcal is equivalent to 1000 cal and to 4.186 kilojoules (kJ).

Here are some reference energy values for certain nutrients: 1 g of protein provides 4 kcal, as does 1 g of carbohydrate, while 1 g of fat provides 9 kcal. Water, vitamins and mineral salts provide no calories at all.