The general principle of nutrient density is the concentration of nutrients per amount of food or caloric contribution of that food. The 2015-2020 Dietary Guidelines for Americans (DGA) defined nutrient-dense foods as those that “provide vitamins, minerals, and other substances that contribute to adequate nutrient intakes or may have positive health effects, with little or no solid fats and added sugars, refined starches, and sodium.”
The Nutrient Rich Foods (NRF) Index is a formal scoring system that ranks foods based on their nutrient density (Drewnowski 2010). Besides calories and nutritional richness, the NRF index also considers affordability. As such, it can be used to help identify food that are both nutritious and affordable. The NRF Index is represented by the sum of the percentage of the daily values of 9 nutrients to encourage (protein, fibre, calcium, iron, magnesium, potassium and vitamins A, C and E) minus the sum of the percentage of the maximum recommended values for 3 nutrients to limit (saturated fat, added sugar and sodium). The higher the nutritional value of foods, the better the scores.
Dairy products score exceptionally well in the NRF index, which means they provide many essential nutrients, but few calories, at affordable prices (Drewnowski 2005). Dairy products are considered to be highly nutrient-rich foods (DGA Executive Summary 2015-2020) and is a natural source of many nutrients. For instance, milk naturally contains protein, calcium, phosphorus, potassium, iodine and vitamins B2 and B12 (EFSA). Cheese contains nutrients such as protein, calcium, phosphorus, zinc and vitamins B2, B12 and K (EFSA). Similarly, yoghurt is a natural source of proteins, calcium and phosphorous (EFSA).
- Drewnowski A. Concept of a nutritious food: toward a nutrient density score. Am J Clin Nutr 2005;82:721–3.
- Drewnowski A. The Nutrient Rich Foods Index helps to identify healthy, affordable foods. Am J Clin Nutr 2010;91(4):1095S-1101S.
- EFSA: 2009; 7(9): 1210; 1219; 1223; 1272. 2010; 8(9): 1777. 2010; 8(10): 1725; 1756; 1811; 1814.
- US Departments of Health and Human Services and Agriculture. 2015-2020 Dietary Guidelines for Americans. 8th Edition, 2015. http://health.gov/dietaryguid elines/2015/resources/2015-2020_Dietary _Guidelines.pdf. Published December 2015. Accessed in February 2019.
- 2015-2020 Dietary Guidelines for Americans (DGA) executive summary. https://health.gov/dietaryguidelines/2015/resources/DGA_Executive-Summary.pdf. Accessed in February 2019.