Young : Fasting is the deprivation, voluntary or not, of food, whether or not accompanied by a deprivation of drink. Partial fasting is an integral part of the practice of some religions (Lent, Ramadan, etc.).
From a medical and physiological point of view, it is considered that the fasting period begins from the sixth hour after the last meal. Fasting sets in motion mechanisms of physiological adaptations which are the heritage of the slow process of evolution. Various experiments have shown in the animal model that non-excessive dietary restriction prolongs the lifespan of many species (mouse, rat, rhesus monkey). A study published in Nature in 2016 also showed that this fast is accompanied by a decrease in DNA damage. Over a short period of time, intermittent fasting results in weight and fat loss similar to calorie restriction as well as increased insulin sensitivity. In France, the NACRe network published in 2017 with theNational Cancer Institute a systematic review analyzing all of the scientific literature on the subject and concludes that there is no evidence of an effect of fasting in humans (beneficial or harmful) in prevention or during cancer.