How did we decide which foods were “good,” “very good,” and “excellent” sources of nutrients?
We developed a two-part formula to determine how “good” a food was as a source of nutrients. The first (and most important) part of this formula looked at the nutrient density of each food. Nutrient density is a key idea in nutritional science. It compares the nutritional content of a food to its calorie content. If a food is very high in one or more nutrients, but very low in calories, it can be described as “nutrient dense” because it uses up very little of your day’s calories but is still “thick” with nutrients. If a food is low in nutrients but high in calories, it is the opposite of nutrient dense – we could describe it with the words “nutrient sparse” or “nutrient thin.” A “nutrient thin” food gives you very little in terms of nutrition, but uses up a lot of your day’s calories. Many foods fall somewhere in the middle and are considered “average” in terms of density. They give you a fair number of nutrients and use up a fair number calories; or they give you a lot of nutrients an
