What is Nutrient Density Important ?
No matter how many calories you eat, your micronutrient needs remain relatively constant. At very high levels of calorie intake, it is not very difficult to obtain adequate amounts of all the needed nutrients, but at lower levels, food selections must be made more carefully. The foods eaten must be more nutrient-dense.
Since the dawn of the Industrial Revolution, civilization has been on a steady course towards more sedentary lifestyles which in turn have demanded lower energy intakes. This is especially true in the western societies.
Our anscestors may have burned 3000 - 4000 calories during a day's labour, but comparatively our calorie intakes, today, have declined to an average of 1800 - 1900 per day. These levels are sufficient to supply our energy requirements.
This situation presents a catch-22 situation for modern people - eat more food and risk obesity or eat less food and you risk nutritional deficits.
The solution here is not to eat more, but to eat smarter. In order to stay health, people whose energy needs are low must include more nutrient-dense foods in their daily diets