What defines 'nutrient density' in food?

The concept of 'nutrient density' refers to the measure of how many essential nutrients are contained in a food item relative to its energy content, commonly expressed in calories. Foods that are considered nutrient-dense provide a high level of vitamins, minerals, and other beneficial compounds without contributing a lot of calories. This means that a nutrient-dense food is one that offers significant nutritional benefits for a relatively low calorie cost. Examples include fruits, vegetables, whole grains, and lean proteins.

Foods that have high calorie content, low fat content, or high sugar content do not necessarily contribute to nutrient density. High-calorie foods can often be low in nutrients, thus lacking nutrient density. Low-fat foods can be highly processed and lack essential vitamins and minerals, while foods high in sugar may also provide a lot of energy but very few nutrients. Therefore, the correct definition of nutrient density focuses on the relationship between nutrient content and energy content, which is why this option is the most accurate.