Policy Research for Front of Package Nutrition Labeling: Developing and Testing a Summary System Algorithm. 2.7.4 Type of Scoring System

05/01/2011

Systems that produce a numeric score using negative and positive nutrients are calculated either by sums (subtract the negative subscore from the positive subscore or vice versa) or as a ratio of the two subscores. Ratios can be greatly affected by small differences and, when tested against sums, did not correlate as well with an overall index of diet quality (Fulgoni et al., 2009); thus, ratios are not recommended.

Whether to score foods across the board or by food categories is also a consideration. As discussed in Section 2.2, across-the-board scoring systems can also be used to rank foods within food groups, but category-specific criteria incorporate intrinsic differences in foods so that certain nutritional qualities of specific foods are accounted for (e.g., vitamin B12 only in animal foods).