Further analyses of our final algorithms could include the following next steps:
- assessing additional nutrients using the new approach to identify nutrients for a nutrient density algorithm,
- assessing alternative weighting of nutrients,
- creating a database of additional brand-specific foods and a calculator to determine scores using the selected system,
- comparing scores or rankings for foods with rankings of foods using other existing summary systems,
- conducting initial consumer testing of the selected FOP summary system,
- conducting an experimental study to measure changes in consumer behavior in response to the system, and
- studying consumer response and behavior for an identified summary system algorithm in comparison with consumer response and behavior for nutrient-specific systems.
Several important issues regarding determination of an index to measure nutritional quality of foods have been addressed in this report. Some general questions still remain regarding the development and testing of nutrient density-based FOP systems.
Which positive nutrients are most important in lowering risk of chronic disease? The evidence for single "positive" nutrients in the prevention of chronic disease is not as well established as for "negative" nutrients such as saturated fat. Longitudinal studies of diet and disease relationships are needed to help identify and quantify (for weighting) nutrients that best predict lower disease risk.
What is the best method to validate a nutrient scoring system? We discussed previously the limitations of validation methods. There is no gold standard to evaluate how well a system ranks foods and predicts chronic disease risk. Longitudinal studies will be needed to test the effects of using the system with consumers on dietary quality and health outcomes.
How well will consumers understand and use a nutrient density-based system? Addressing this issue was not within the scope of this project. Knowledge about the ability for consumers and subpopulations who are at particular risk of obesity and chronic disease to understand and use a nutrient density system is extremely important.
How do consumer understanding and use of a nutrient density system compare with other summary systems and with nutrient-specific systems? Previous research suggests that consumers can identify healthier food choices more easily with a nutrient-specific system with traffic light colors of red, yellow, and green than a summary check mark type system (Hersey, Wohlgenant, Kosa, Arsenault, & Muth, 2011). Assessments of consumer understanding of nutrient-specific systems compared to nutrient density scoring systems or graded rating systems are limited.