Overview and current knowledge

It is essential for humans to eat a varied and balanced diet. We have known for a very long time that no single food provides everything that the human body needs to stay healthy. 

Modern diets, with their superficial abundance and diversity, ought to very easily provide all the essential nutrients and micronutrients that the body needs to function under optimal conditions. 

However, this is not always the case.

Our diets no longer provide sufficient micronutrients 

According to the Food and Agriculture Organization of the United Nations (FAO), more than 2 billion people in the world may suffer from micronutrient malnutrition. Vitamin A, iron and iodine deficiencies are the most common forms of micronutrients malnutrition in the world.

In other words, the conclusion reached is that despite their high calorie values, typical modern diets may contain low levels of micronutrients, and in some cases none at all!

What does "empty calories” mean?

When the micronutritional content of a food is high and the energy (or calories) it contains is low, then the food has a “high nutritional density”. This is the case, for example, for fruit and vegetables.
On the contrary, a high-calorie, low-micronutrient food has a “low nutritional density”.
Low nutritional density products are said to be a source of “empty calories”. These foods tend to contain large amounts of sugar and/or fat, examples of which are: cakes, pastries, cereal bars, sweets, sugary drinks, ice creams, prepared (deli-type) meats, chips, hamburgers and even many pre-prepared “ready-to-eat” dishes.

Variations in micronutritional requirements from person to person

In terms of the effects on us of micronutritional deficiencies, we are not all created equal! For some people the impact is minimal, whereas for others deficiency can cause dysfunctions, increasing susceptibility to disease or aggravating existing conditions.

Medical science can now explain some of these inequalities. 

Visuel bactéries

The ability to assimilate micronutrients varies from person to person.

Good assimilation occurs when the digestive organs are functioning well (e.g. when the liver and pancreas produce high quality secretions, such as bile) and when the intestinal ecosystem is correctly balanced, which requires a healthy microbiota (or intestinal flora). 
This is why a course of antibiotics, a stomach bug, chronic digestive disorders (constipation, bloating, etc.) or prolonged stress has consequences on the assimilation of micronutrients which cannot under these conditions be optimal.

Every individual has micronutritional requirements specific to them.

They vary as a result of genetic predispositions and differences in lifestyle (exercise levels, stress levels, etc.). Consequently, some individuals use up only small amounts of micronutrients, whereas others use up more.

The amount of micronutrients we use up on a daily basis varies as we age. 

The amounts used up increase when the body is physically or mentally stressed especially when this stress is intense or prolonged.
Usage levels are higher for women during pregnancy.
They are also influenced by environmental factors such as whether the individual smokes, drinks alcohol or is ill, particularly with a long or chronic disease (which can cause inflammatory conditions and/or digestive disruptions).
Finally, taking certain medicinal products can deplete our reserves of some micronutrients. 

Sources :

  • Didier Chos (2014) En bonne santé grâce à la micronutrition. Editions Albin Michel.
  • Etude ESVITAF : Herbeth B, Potier de Courcy G, Sancho J, Bourgeay-Causse M, Carreguery G, Chau N, Delacoux E, Le Devehat C, Lemoine A, Mareschi JP, et al. "ESVITAF". Survey on  the vitamin status of the French: relationships between nutrient intake and biochemical indicators. ActaVitaminol Enzymol. 1985;7(3-4):207-15.
  • Etude de Bourgogne : de Carvalho MJ, Guilland JC, Moreau D, Boggio V, Fuchs F. Vitamin status of healthy subjects in Burgundy (France). Ann NutrMetab. 1996;40(1):24-51.
  • Etude du Val de Marne : Hercberg S, Preziosi P, Galan P, Deheeger M, Papoz L, Dupin H. Dietary intake of a representative sample of the population of Val-de-Marne; III. Mineral and vitaminintake. RevEpidemiol Sante Publique. 1991;39(3):245-61
  • Etude SU.VI. MAX : Hercberg et al. Communiqué de la coordination nationale SU.VI.MAX. 1998.
  • Vernay M et coll. Statut en vitamine D de la population adulte en France : l’Etude nationale nutrition santé (ENNS, 2006-2007). BEH 24 avril 2012/ n°16-17.