Various beliefs and injunctions (“Breakfast is the most important meal of the day”, “If you don’t eat every 4 hours, you will pass out”, “You see your muscles melting”) explain why fasting can be worrying… In a society of food abundance, deciding not to eat, even if it is simply a question of skipping a meal, is often badly perceived, when it is established that we eat a lot, probably too much.
“However, if prolonged fasts without real medical supervision can be dangerous [une femme est décédée l’été dernier en Indre-et-Loire lors d’un jeûne de plusieurs semaines, faute de suivi et d’encadrement spécialisé, NDLR], skipping a few meals does not put a healthy person at risk if they continue to hydrate and, above all, can be beneficial for weight and health” says Pr Antoine Avignon, head of the nutrition-diabetes department at the Montpellier University Hospital Center.
What type of fast to choose?
Our specialists believe that fasting, short and well conducted, with kindness and respect for oneself, is good: it allows you to regain your healthy weight without depriving yourself of the rest of the time, and without disrupting your diet or counting your calories.
There is no single type of fast for a woman’s profile, or to guarantee a number of pounds to lose. According to Dr. Bourdua-Roy and Sophie Rolland, fasting specialists, the only essential point is “the constancy” of the practice.
Stopping eating one morning (or even 24 hours) once a month won’t make the pounds fly away. “The solution is in the regular use of fasting to take full advantage of its long-term benefits and to lose weight gently, over several weeks or months”, explain our experts.
How it works ?
Losing weight by fasting is not simply a question of calories that by avoiding swallowing we would “save” to lose weight: fasting is not an extreme “calorie restriction”. In reality, fasting is effective for losing weight because, after a certain time without eating, it triggers a metabolic and hormonal shift that is beneficial to weight loss: it forces the body to produce its own energy by activating metabolic pathways that are at rest when we eat.
What happens when we stop eating? During the first hours, it is the reserves of the liver, in the form of glycogen, which are mobilized to produce energy (in the form of glucose).
These reserves will be exhausted within 12 to 16 hours after the last meal (depending on their quantity, the metabolism, or the physical exercise practiced during this interval of time). The body must then look for other fuels to function, and will use fatty acids and ketone bodies (produced from body fats) which will also be produced by the liver. Once the level of insulin circulating in the body has decreased (it is this which, secreted following food intake, orders the storage of fat), the body can thus draw directly on its fat reserves, which will be destocked and burned: the famous lipolysis so hoped for is active, will increase over the hours… and can help to lose weight.
Our Experts:
- Pr Antoine Avignon, head of the nutrition-diabetes department at the Montpellier University Hospital Center
- Dr. Evelyne Bourdua-Roy, general practitioner
- Sophie Rolland, neuroscientist
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- Calculate your BMI with our online tool
- Slimming: 12 tips to lower the glycemic index
