The World's Healthiest Foods explains that "nutritional value" is a measure of how nutrient-dense a particular food is. Nutrient density is a measure of how many nutrients a food contains per calorie unit. Nutrient-dense foods allow people to consume all of the vitamins, minerals, phytonutrients, fiber and essential fatty acids they need while limiting their calorie intake.
Other organizations have taken the concept of nutrient density and added healthy/unhealthy measures to it to generate an overall nutritional value score, according to NuVal. NuVal and other similar rating systems consider the nutritional density of each food, and they adjust the score by crediting foods with nutritional components considered to be beneficial for health, such as fiber, and reducing the overall score for foods with nutritional components considered to be detrimental for health, such as sugar. Other factors considered in calculating the final nutritional value score are protein quality, fat quality and glycemic load. Each food is given a score from one to 100 that is supposed to capture the nutritional value of the food, with better foods scoring higher. NuVal scores are displayed on grocery store shelves next to the foods for sale in grocery stores that subscribe to the service.