Atwater General Factors is a system for allocating energy values to foods. It was developed in the 19th century by the American chemist W. O. Atwater. The energy values (based on the average heats of combustion of each group and corrected for losses in digestion, absorption, and urinary excretion of urea) are 17 kJ/g (4.0 kcal/g) for protein, 37 kJ/g (9.0 kcal/g) for fat and 17 kJ/g (4.0 kcal/g) for carbohydrates.
Nutrient Daily Value Recommendation:
2,000
kcal
(Use FDA 2000 calorie diet as Daily Value reference)