The amino acid molecule, Official dietetics logo

Official dietetics

Klee, the balanced diet logo


Digestion is defined as all the mechanical and bio-chemical processes that ensure the transformation and absorption of foodstuffs. Each food consists of nutrients that can be assimilated easily and directly :

proteins lipids carbohydrates vitamins minerals trace elements

Foods are also classified in 6 groups:

group 1 milk and dairy products proteins of animal origin
that are rich in calcium
group 2 meats, fishes, eggs proteins of animal origin
group 3 fats lipids
group 4 cereals, potatoes
group 5 fruits and vegetables rich in water, mineral salts and vitamins,
facilitate bowel movement
group 6 sugar, sweet products carbohydrates, rapidly assimilated

According to the official dietetics

For a balanced diet, a healthy person must eat food-items from each of these 6 groups in each meal. And the quantities of the nutrients must be adapted according to the physiological needs of each individual.

National Programme of Nutrition and Health, in France makes following recommendations for a balanced and varied meal as far as dietetics is concerned:

It is also advised that one must do physical exercise: walk, climb stairs, ride a bicycle...

Official dietetics is a scientific discipline that depends on chemists. Each food item is analysed in a very precise manner.

For example, for 100 grams of an item:

product calories water proteins carbohydrates lipids fibres
apricot 47 Kcal 85 g 0,8 g 10 g 0,1 g 2,1 g
lentil 315 Kcal 10,2 g 24 g 50,4 g   11,2 g

product potassium magnesium phosphorus calcium iron vitamin C
apricot 315 mg 11 mg   16 mg   7 mg
lentil 700 mg 100 mg 300 mg 50 mg 8 mg  

As a dietician is aware of daily recommended quantities and the deficiencies of a sick person, he can prescribe a strict and scientific medical diet, that point out the weight of each food that is to be eaten.

On the other hand, a healthy person may be repulsed by mathematical calculations. In order to lose a couple of kilos, she will often be happier with a summary: apricot has lesser calories as compared to lentils and is less rich in nutrients. She will conclude that in order to achieve weight-loss, eat lesser lentils and more apricot! Of course not: it is not so easy!

More about: 1) Introduction --- 2) History --- 3) Principles

- Top of page -

How to cook in a manner based on dietetics

1 - I am healthy

2 – I am looking for dietetic recipes

3 – I want to monitor my food more

And I want to eat what is best for my body type and my lifestyle: I consult a dietician who can advise me.

Top of page <- To -> 1) Introduction --- 2) History --- 3) Principles

1 - Introduction

We have called the dietetics that is mostly accepted in present day West: Official dietetics. We have done this in order to differentiate it from the dietetics that originates from age-old traditions and alternative dietetics often disputed by Western Medicine.

Official, scientific dietetics is based on epidemiological studies and physico-chemical analysis. This is the reason why supporters of official dietetics reject historical and empirical dietetics, which are based on experience and practice. This is the reason why they mistrust alternative diets or dietetics that, according to them, have a restrictive or inaccurate vision of problems.

What is surprising is that we find similarities between official dietetics and historical and alternative dietetics: the idea of dietary balance.

In all eras, eating well is the guarantee of maintaining one's health. Eating well signifies eating food-stuff that is adapted to one's constitution and lifestyle. In other words, eat balanced diet. In all dietetics, dietary unbalance favours appearance of dietary problems and even diseases (cancer, cardiovascular diseases).

Scientific knowledge of foods is progressing: now, when one eats a lamb chop or salmon, carrots or cheese, one can know the amount of lipids, proteins, carbohydrates or vitamins that one consumes.

While the present-day dietetics continues to augment its knowledge about foods and complex physico-chemical phenomenon of digestion, at the same time it must face a new challenge: reducing obesity and food-related diseases that are increasing all over the world.

-> 2) History --- 3) Principles

- Top of page -

2 - Some history

As opposed to the Chinese and Ayurvedic medicine, old Hippocratic medicine is rigid about adhering to the texts of ancient masters. It has not evolved with new discoveries in the fields of anatomy, physiology and chemistry. From 16th century onwards, Hippocrates' and Galen models have been more and more contested. In the 17th and 18th centuries, the rise of Cartesianism (belief in Descartes' philosophy) and rationalism facilitated the development of sciences on new basis: Human body was no longer regarded as the symbol of universe. It was objectivized and became a machine (L'homme machine, Julien Offroy de La Mettrie, 1748 - The Man-machine). Body becomes independent of its environment. Its organs can be repaired (even replaced from 20th century onwards) just like one repairs a machine. The link between body and soul is more and more forgotten. Every time there is a malfunctioning, medicine tries to find a corresponding remedy.

Often, this mechanistic vision of medicine still continues to dominate. But it has helped in making important scientific discoveries for improving health.

Scientific progress

Since 1609, Galilee observed infinitely small objects through what he was to name the microscope in 1625. Around 1616, William Harvey correctly described the discovery of blood circulation. In the 18th century, the Hippocratic theory of digestion (cooking of food-stuffs) was definitively abandoned: gastric juice and the chemical nature of digestion were discovered. The principle of vaccination against smallpox, discovered by Chinese medicine, was perfected by Edward Jenner in 1798. In 19th century, Claude Bernard pursued the study of digestion: study of pancreatic juice (1849), manufacturing of sugar by liver (1855).

Louis Pasteur

From 1854 onwards, Louis Pasteur (left photograph) studied fermentations (vinegar, wine, beer) and invented pasteurisation in 1865. Existence of vitamins was discovered slowly between the end of 19th century and beginning of 20th century (Casimir Kunk, 1912).

From Pasteur onwards, the progress became faster: discovery of microbes, virus, vaccines, and antibiotics. It seemed as if the curse of epidemics and infections had been arrested.

The progress of surgery, pharmacy and hygiene in the 20th century has resulted in indisputable increase in the life-span.

Official medicine has not completely rejected all the earlier medical traditions: western medicine and its pharmaceutical industry will search the molecules that can heal current diseases in the traditional pharmacopoeia. Our medicines often stem from the traditional Hippocratic, Ayurvedic, Chinese, or the traditional-practitioners of Madagascar or Amazonia pharmacopoeia.

Modern medicines are no longer the decoctions or infusions of plants, but are made of chemical molecules: therapeutic efficiency of traditional substances has been increased and their secondary effects have been decreased.

As the risks of early death decreases, man wishes to live well and as long as possible. In Middle Ages, the absence of reliable medicines had forced physicians to develop Regimen of health in order to prevent diseases. Plants were used for treatment.

Between 17th and 20th century, the progress of medicine made one forget the notion of Health Diet. Physicians devoted themselves only to struggle against microbial disease, followed by viral diseases.

Prevention and dietetics

Today, in face of an unprecedented increase in obesity and cardiovascular diseases all over the world, we are rediscovering that many diseases are linked to eating habits and that correct eating habits, along with a healthy lifestyle, lets one live longer! We are rediscovering the concept of prevention: maintaining health in order to avoid falling sick and then requiring use of medicines. This is the reason why the profession of dietician developed in the second half of 20th century.

Today, we are aware that dietetics, including scientific dietetics, is progressive: in the 1950s, one praised the vitamins to the skies. Then one mistrusted lipids and carbohydrates. 21st century saw the discovery of Omega 3 or the anti-oxidants. Some present these as miracle pills that are the key to longevity. And just like Hippocrates used to do 24 centuries ago, these new prophets of dietetics tell us that longevity pills can be found in our basic food: in fruit and vegetables, in dairy products or fish.

The research continues. What new information will we have tomorrow that will help us eat better and remain healthy?

1) Introduction <- To -> 3) Principles

- Top of page -

3 - Principles of dietetics

Digestion is now defined as all mechanical and bio-chemical processes that ensure transformation and absorption of foods. We are more and more aware about the nutritional value of foodstuffs. Diets adapted to needs of healthy or sick people are defined in a different manner.

1986 saw the birth of a new paramedical profession in France: dietician. A dietician is a specialist in the field of nutrition who can advise and educate in all areas linked to consuming food. She deals both with healthy (sportsmen, pregnant women, elderly) and sick people who need an adapted diet (obesity, diabetes, digestive, metabolic pathologies etc...).

The old dietetics tried to classify foodstuffs. With the help of its means for scientific analysis physico-chemical analysis, the official dietetics has defined simple elements in each food-item: Each food-item is made of directly available organic or mineral substances that need not be transformed by the digestion. These are called nutrients: macro-nutrients (proteins, lipids, carbohydrates) and trace micro-elements (vitamins, minerals and trace elements).

Foods are also classified in 6 groups according to their nutritional characteristics.

group 1 milk and dairy products proteins of animal origin
that are rich in calcium
group 2 meats, fishes, eggs proteins of animal origin
group 3 fats lipids
group 4 cereals, potatoes
group 5 fruits and vegetables rich in water, mineral salts and vitamins,
facilitate bowel movement
group 6 sugar, sweet products carbohydrates, rapidly assimilated

In France, balanced diet is defined with the help of RDA (ANC) concept: recommended dietary allowance. Averages of necessary nutrient intakes needed to cover physiological needs of a healthy person according to his age and sex were calculated.

Food pyramid

RDA has become an official benchmark in food education policy for health in order to help determine food rations that are suitable with regards to French culinary traditions. Recommended daily quantities are: 11-15% of proteins, 30-35% of lipids and 50-55% of carbohydrates including 10% of simple carbohydrates. Variety in food, too, is recommended: a food-item from each of the 6 groups must be present in every meal.

Food pyramid presented by Celnat

This pyramid (presented by Celnat) is a food model that was proposed in 1992 in the U.S.A. by the Health Ministry (Department of Health and Human Services, HHS) on the basis of researches conducted by the Ministry of Agriculture (United States Department of Agriculture, USDA) that takes into account the most recent knowledge concerning nutritional science.

For healthy people, the official dietetics recommends on priority basis a diet that is balanced in nutrients and diversified. Therefore, it considers the alternative dietetics that does not respect this food balance or the diversification of foodstuffs (dissociated diets, vegetarian, vegan or raw food diets...) very harmful.

Physicians are not the only ones who work in the field of dietetics:
In France, the Health Ministry has created a national program for nutrition-health so as to prevent diseases linked with eating habits (cardiovascular diseases, obesity, diabetes, cholesterol). In developed countries, all women's magazines have columns about dietetics and advices for slimming. Agribusiness is often accused of being the cause of problems of obesity but it, too, participated in this boom in concerns about dietetics by creating, at the end of 1990s, medical foods or "nutraceuticals". These were actually health-enhancing foods that were considered especially beneficial for health (milk or cereal products).

1) Introduction --- 2) History --- 3) Principles <- To

- Top of page -