Final answer:
Energy values in food composition databases are based on the Atwater system, which calculates the average calories per gram of proteins, carbohydrates, and fats. These values consider the fiber content in carbohydrates, which reduces the total caloric value.
Step-by-step explanation:
The energy values in food composition databases are based on the Atwater system. This system takes into account the different chemical constituents of food, namely protein, carbohydrate, and fats. To calculate the energy content of a food, the quantities of these macronutrients are multiplied by their respective average calories per gram.
This calculation considers carbohydrates to be somewhat lower in calories due to the fiber content, which is an indigestible carbohydrate. The use of bomb calorimetry has historically helped define these average caloric values by measuring the energy released from burning whole foods in a controlled setting.
Nutrient and energy density knowledge allows for making healthier food choices by understanding the energy these nutrients provide. Moreover, the dietary energy factor provides insights into the ratio of energy spent producing the food compared to the metabolic energy it contains. This can guide sustainable and healthy diet choices.