There are a few possible reasons you may see negative nutrient values in your output files.
Database maintenance
The way NCC maintains our database can, in very limited cases, lead to negative nutrient values in the output files when records are restored from an older version of NDSR into a newer version of NDSR. For the most part this is very rare, though we are aware of some instances where foods entered into prior versions of NDSR that are restored into NDSR 2025 or subsequent versions may result in negative non-heme iron values. If you notice negative nutrient values in output file 02 (food file) that are not due to any of the reasons below, please contact us at NDSRhelp@umn.edu and we can provide you with information so you can correct the negative nutrient values in your data set.
Food Formulations
When creating formulations for multi-ingredient foods in the database, we may subtract components such as water, sodium, or potassium. Therefore, when you look in output file 01 (component/ingredient file), you may see negative nutrient values for those components of a database food. For example, when making a fast food hamburger we may subtract sodium to match the nutrient value provided by the restaurant. The nutrient totals for the food will be correct (not negative) in output file 02 (food file). The negative nutrient values in output file 01 are intentional and do not need to be addressed.
User Recipes
If you create a User Recipe that includes a negative amount, you will see that negative amount, and therefore negative nutrients, in output file 01 (component/ingredient file). If the negative amount was intentional and is not causing negative nutrient values in output file 02 (food file), then this does not need to be addressed. If you are finding negative nutrient values in output file 02 for a User Recipe that you created, then you should correct the User Recipe, and reselect the corrected User Recipe into the record. If you are finding negative nutrient values in output file 02 for a User Recipe that NCC sent you for a new food request, please contact us at newfoods@umn.edu.
View/Paste Ingredients Feature
Another action that can result in negative nutrient values in output file 01 (component ingredient file) and output file 02 (food file) is using the View Ingredients feature to paste the ingredients of a mixed dish into an assembled food. If the pasted formulation includes a negative amount (that would typically only be seen in output file 01), it will now be present in both output file 01 and output file 02 because it is part of the assembled food. You will have to determine on a case-by-case basis if the negative value in the assembled food is correct, depending on the changes you made to the ingredients. You may consider summing the nutrient totals for the components of the food to ensure that the net nutrient totals are not negative.
Entering negative amounts in a record
If you enter a negative amount in a record, then you will see negative nutrient values in output file 02 (food file) and output file 01 (component/ingredient file). If the negative amount was entered into the record in error, then correct the negative amount in the record.
If the negative amount was entered intentionally, then you may not need to address it. For example, if your study is looking at daily nutrient totals (not conducting analysis at the food level), and you used a negative amount to subtract lettuce from an NDSR sandwich that includes lettuce, then your daily totals would be correct, and you would not need to make any changes. If you are intending to conduct analysis at the food level, then you may want to avoid entering negative amounts in the record.