A thunderclap in the musical ecosystem: we learned in November 2015 that the singer of the Coldplay group, Chris Martin, pampered his voice, not by multiplying the honey milks, but by regularly practicing the fast.

"I noticed I was singing better," he told Radio Fresh 102.7, "and I got new recognition for the food."

A few months later, we also learned, via the Slate.fr site, that this punctual food ascetic practice practiced by Seneca (in the hope of boosting his intellectual capacities) or by the former wife of Chris Martin, Gwyneth Paltrow (in the hope of preserving its influential welfare status), was encouraged in Silicon Valley, never running out of ideas to maximize the performance of its employees.

Thus, the start-up Nootrobox, specializing in drugs supposed to improve cognitive functions, she recommends to his team to fast every week from Monday evening to Wednesday morning. With results that prompted her to create the WeFast group on the Slack app ("We are fasting"), which now has several hundred followers. Not bad…

The French, also followers of fasting

But it is less than the four thousand members of the French Federation of fasting and hiking today. This is especially less than the 15 to 20% of Germans who have already practiced a long fast under medical supervision.

Thus, at a time when detox, cures of silence and various disconnections are needed like the body therapies of our time, fasting water (based on water, fruit juice, herbal tea and broth) makes talk about him.

No wonder, according to Eric Roux, spokesman for the Observatory of popular kitchens: "There is today a re-ritualisation of the plate that, admittedly, can take very moderate forms, but responds to a the pendulum effect that has always been observed in history, he explains: In the Catholic tradition, for example, carnival (period of excess) precedes Lent, under the various dietary trends that we observe. At the present time, there are various legitimate concerns (for example, reducing meat consumption), the unconscious expression of an ancestral cultural trait can be read, and so far as everything can be found in abundance and out of season we need, by reaction, to create constraints, frames, rites to become aware of what we must or not have access. "

Who are the "fasting"?

In France, converts today would respond to a specific sociological profile, identified by Jean-François Barbier-Bouvet, in 2010, in a survey of five hundred fasters and entitled "Fasting today, a personal and spiritual practice" .

A mature audience (between 45 and 60 years old), mostly women (71%) and having higher education (80%). A population that, far from doing penance in pilgrim sandals, considers itself also "good living" the rest of the year.

Germany, precursor of fasting as therapy

If this inflation of converts owes nothing to the French medical profession (reluctant on the subject), it owes a lot to the German researchers.

A country where fasting, far from being confined to the clichés bobos bios, is reimbursed by social security and is practiced in public hospitals.

Germany, in fact, played an important role in the chaotic history of the legitimation of fasting as a therapy in its own right.

Fasting: where does the method come from?

The story goes back to the end of the 19th century. In 1880, the American doctor Henry S. Tanner rose to the challenge of fasting forty days and made headlines in the United States.

A few years later, his colleague Edward Hooker Dewey published his research on the subject, coming up against the reluctance of the medical profession. Because at the time, fasting is still linked to spiritual and religious diktats.

Indeed, in different civilizations, from Islam to Shintoism, there are rules relating to food which prescribe to believers a renunciation, limited in time, to food.

"A healthy mind in a healthy body"

Purification of the soul, penance, depuration, spiritual enlightenment or redemption are the core of fasting.

Asceticism is as old as the world, reminded Odon Vallet, the specialist of world religions: "It was already practiced in ancient Greece, and perhaps even more in the Indian world, or even further in the civilization of the Indus, which has found its continuation in Indian yoga. "

Difficult to secularize the practice.

But in Germany in the 1920s - the golden age of the liberation of bodies by nudism, crudivorism - fasting gained the interest of Dr. Buchinger, who devoted himself to the study of internal hygiene and powers self-healing physiology.

In the 1950s, the Russian psychiatrist Yuri Nicolaev tried experiments (for example, penguins became professional fasters), which led to the integration of fasting into politics in the Soviet Union in the 1980s. public health.

Studies that, as the documentalists Thierry de Lestrade and Sylvie Gilman remind us, were never translated during the Cold War and still sleep in the basements of the Academy of Sciences in Russia.

Assumed health virtues

In France, it was not until the broadcast of their documentary "Fasting, a new therapy", in 2011, for a wide audience to discover its virtues via a scientific and rational approach, and no longer spiritual and religious.

It taught, for example, that fasting is indicated to any individual wishing to regenerate his organism, especially if he opts, for the rest of the year, for a heavy diet.

But it is also recommended for asthmatics, diabetics, people with arthritis or cancer patients treated with chemotherapy.

"The success of the documentary was unexpected and unexpected," says Thierry de Lestrade, "because he was responding to a strong demand: to look for another relationship to the body, to care, to old age, to chronic diseases."

Physicians in need of this practice

But faced with this craze, the medical authorities impose a complete silence. When they do not throw out the question: "Do not worry!"

"The French doctors are poor, analyzes the documentary filmmaker.Their studies devote only few hours to nutrition.They do not know anything about the mechanisms of fasting."

In 2015, Dr. Valter Longo, Director of the Institute of Longevity at the University of Southern California, published a study demonstrating the effects on animals of caloric restriction on Alzheimer's disease and certain cancers. (tumors reduced by 45%).

"Minds are opening slowly in France, in the medical profession, but it always comes from individual initiatives of doctors who come into contact with me, and who realize that the only way to train is to go to Germany. Thierry de Lestrade continues: With regard to the order of doctors: absolute reluctance The Academy of Medicine has also published, under the pen of Jean-Marie Bourre, an article against the charge against fasting in Le Figaro in 2013 , just after the publication of my book. "

The skepticism is based in particular on the lack of perspective on the long-term effects of the diet. Sign of opening however: in 2014, a report of the National Institute of Health and Medical Research was published on fasting as a preventive and therapeutic practice.

Following this "a senior official of the Ministry of Health had wished to organize a symposium on this subject". She failed to convince her colleagues.