<P> Based on the work of Atwater , it became common practice to calculate energy content of foods using 4 kcal / g for carbohydrates and proteins and 9 kcal / g for lipids . The system was later improved by Annabel Merrill and Bernice Watt of the USDA , who derived a system whereby specific calorie conversion factors for different foods were proposed . This takes cognizance of the fact that first the gross energy values of the protein , fats and carbohydrates from different food sources are different , and second , that the apparent digestibility of the components of different foods is different . </P>
<P> Based on the work of Atwater , it became common practice to calculate energy content of foods using 4 kcal / g for carbohydrates and proteins and 9 kcal / g for lipids . The system was later improved by Annabel Merrill and Bernice Watt of the USDA , who derived a system whereby specific calorie conversion factors for different foods were proposed . This takes cognizance of the fact that first the gross energy values of the protein , fats and carbohydrates from different food sources are different , and second , that the apparent digestibility of the components of different foods is different . </P>
the atwater general factor for dietary carbohydrate is
the atwater general factor for dietary carbohydrate is
4 kcal / g
4 kcal / g