|Compensated 4-4-9 Method of Calculating Calorie Ratios|
The "Compensated 4-4-9" Method of Calculating Calorie Ratios - For non-USDA brand name and restaurant foods, CyberSoft uses its proprietary "compensated 4-4-9" method to calculate "% calories from" and the "calories from" values for Protein, Carbohydrates, and Fat. These values are used to derive the "PCF Ratio" (the % calories from Protein, Carbohydrates, and Fat). NutriBase displays the PCF Ratio in all Recipes, nutrient intakes, Meals and Meal Plans. (NutriBase provides a User Preference option to display the "CPF Ratio" which sequences the calorie ratio in the order or Carbohydrate, Protein, and Fat.)
Several factors make the straight 4-4-9 method less than ideal when applied to actual published data. For one thing, many food makers consider any nutrient containing fewer than 5 calories to be "nutritionally insignificant." For this reason, many food makers "round off" their published values for protein, carbohydrates, and fat. Sometimes they publish a value of "<1.0 gram" for fat, which should provide a conservative figure, but it could also mean that the fat content is anywhere from 0.99 grams down to 0.0 grams. When a food item contains only a few calories, the "insignificant" rounding of fat values can have very significant and misleading consequences.
One consequence of this practice of rounding nutrient values is that when the caloric values for protein, carbohydrates, and fat are added up, they very rarely match the calorie values published by the food manufacturer or restaurant. This means that to simply multiply fat grams by 9 and calculate the resulting value as a percentage of the total calorie value will often result in a very misleading value for % Calories from Protein, Carbohydrates, or Fat.
To more accurately represent "% Calories from" values, CyberSoft developed a simple method for calculating percentage contents of all sources of calories. It is called the "compensated 4-4-9 method." Here's how it works:
1) Calculate the total calories from the calorie sources by multiplying protein grams by 4, carbohydrate grams by 4, and fat grams by 9. Sum these derived values to produce a "total derived calories" value.
2) Assume that the food maker's published total calorie value is correct. Compare the "total derived calorie" value to the food maker's published total calorie value. If the derived value is lower or higher than 100% of the published value, adjust all the non-zero nutrient values in exactly the same ratio to produce a 100% correlation with total calories. This "unrounding process" results in "% calories from" values for Protein, Carbohydrates, and Fat that add up to the published total calories and that also add up to 100%.
This method is one way to assure the highest possible degree of accuracy from the published nutrient data currently available from food makers today.
For USDA "formulated foods" - food items that include multiple ingredients - CyberSoft used the 4-4-9 method of calculating calorie ratios.
For USDA data, which includes the Atwater Conversion Factors for Protein, Carbohydrates, and Fats, food items, CyberSoft performed calculations based on the conversion factors provided by the USDA..
For food items listed in the Vitamins and Medical Nutritionals section of NutriBase (multiple vitamins, supplements, enteral and parenteral products), CyberSoft calculated calorie ratios by using the manufacturer's information regarding calorie percentages.