In relation to energy content, there was a significant variation (50.1 Kcal/100 ml) between the studied samples of natural milk, demonstrating the importance of control related to the nutritional content of donated human milk in human milk banks. The energy content of the milk is mainly related to overall fat content, as the energy density of this macronutrient is responsible for most of the calories in human milk. In this study, the energy values were lower in samples where the fat content was lower.