What does 4kcal per gram mean?

"4 kcal per gram" refers to the amount of energy provided by a substance when consumed. Specifically, it indicates that for every gram of that substance, the body can extract 4 kilocalories (kcal) of energy, which is a measure commonly used in nutrition. This value is particularly associated with carbohydrates and proteins, meaning they provide energy that can be used by the body for various functions. In contrast, fats typically provide about 9 kcal per gram.