|The Compensated 4-4-9 Method|
|For non-USDA brand name/restaurant foods and Canadian Nutrient Data, CyberSoft developed the “compensated 4-4-9” method of estimating calories and PCF ratios. In NutriBase, “PCF Ratio” refers to the percentage ratio of calories from Protein, Net Carbohydrates, and Fat, in that order.
When applying the “straight 4-4-9 method” to actual published data, several factors make this method less than ideal. For one thing, many food makers consider any nutrient containing fewer than 5 calories to be “nutritionally insignificant.” Nutrition Facts labels report all fat amount less than 0.5 grams as “0” (zero). Sometimes they publish a value like “<1.0 gram” for fat, which means that the fat content is somewhere from 0 to 0.99 grams. When a food item contains only a few calories, the “insignificant” rounding of nutrient 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 rarely match the calorie values published by the food manufacturer or restaurant. This means that to multiply fat grams by 9 and calculate the resulting value as a percentage of the total calorie value will result in a misleading value for % Calories from Fat (or any other percentage value).
To more accurately represent “% Calories from” values, CyberSoft develop¬ed a simple method for estimating “% calories from” values of the various nutrient components. We call this the CyberSoft “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, estimated net carbs (carbohydrates minus total dietary fiber) 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 “un-rounding” 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 - although crude - is arguably the best way to assure the highest possible degree of accuracy from the nutrient data currently available from food makers today. Since the Atwater Conversion Factors are not available for most multi-ingredient brand named foods, this method provides numbers that are likely to be more accurate overall than numbers calculated using the straight 4-4-9 method.
For USDA “formulated foods” - food items that include multiple ingredients - CyberSoft used the 4-4-9 method of calculating calorie ratios. CyberSoft's decision to not impose the compensated 4-4-9 method on USDA data produced some calorie ratio totals of less or greater than 100%. For USDA data, which uses 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. (These values do total 100%.)
This topic updated 06/24/2015