Nutrient dense foods have the highest nutrient-per-calorie ratio, meaning that they supply more nutrients compared to the number of calories they supply.

In contrast to this, energy dense foods supply more calories compared to the number of nutrients they supply. In general, energy dense foods are high in fats and refined sugars. It is of great concern that the American diet is becoming more and more energy-rich but nutrient-poor.

Nutrient density overall is on the decline. Modern vegetables, whole grains and other nutrient-dense foods provide less nutrition now than they have in decades past. This is an alarming trend given that currently available vegetables and fruits are still your most broadly nutrient-dense foods with superior health-promoting qualities.

According to Dr Joel Fuhrman, the Top 10 Nutrient Dense Foods include a large number of dark leafy green vegetables including kale, spinach and swiss chard.