The modification removing unsaturated fat from the algorithm results in changes in scores regardless of whether the food contains unsaturated fat because the total number of positive nutrients in this algorithm is 7 and the sum of the positive nutrient percentages was divided by 7 instead of 8 in the baseline algorithm. In general, if a food did not contain unsaturated fat, then the score increased because the positive nutrients were now divided by 7 rather than 8. Conversely, in general, if a food contained unsaturated fat, then the score decreased when it was removed from the algorithm. The mean and distribution of algorithm scores by major food groupings using the modified algorithm scoring foods on a per 100 kcal basis (NDS2KCAL) and a per RACC basis (NDS2RACC) are presented in Figures F-1 and F-2.
The overall mean scores of the 570 foods with the modified algorithms were similar to the overall mean scores for foods using the baseline algorithm. The rankings of the mean scores from the major USDA food groupings changed slightly. Fruits ranked first for both algorithms, although the mean score for fruits increased with the modified algorithm. The scores for most fruits increased because they do not contain unsaturated fat; however, the score for avocado decreased with the modified algorithm because avocados are high in unsaturated fat (i.e., from 4.42 to 3.02 on a per 100 kcal basis and from 9.89 to 6.76 on a per RACC basis). Vegetables and eggs reversed within the second and third rankings on a per kcal basis with the modification, and scores for eggs decreased because they contain some unsaturated fat. As in NDS1, potato chips still had higher scores than baked potatoes, but the gap was smaller because the score for potato chips decreased and the score for baked potatoes increased with the removal of unsaturated fat from the algorithm. Dairy scores generally increased because they contain relatively small amounts of unsaturated fat and high amounts of other positive nutrients. A few foods in the dairy group that contained more unsaturated fats (e.g., cream substitutes) had lower scores with the modified algorithms (NDS2KCAL and NDS2RACC). The mean score for legumes/nuts decreased slightly. Although the scores for all of the nut foods decreased, some of the bean scores increased. The top-scoring food in the legume/nut group was almonds; its score decreased from 7.33 to 6.11 on a per 100 kcal basis and from 12.65 to 10.54 on a per RACC basis. The largest decrease in mean food group scores with the modified algorithm was for the fats, oils, and dressings group because of the high unsaturated fat content of many of the foods in this group. For example, the top-ranking food, olive oil, decreased from 1.14 to −1.39, and margarine decreased from −1.78 to −4.06 on a per 100 kcal basis. The fats and oils remained the group with the lowest mean score on a per 100 kcal basis but decreased from the fifth to the eighth ranking on a per RACC basis.