She is credited with singer Adele’s flash weight loss. It was also the most searched diet on Google in 2020 in Canada. The Sirtfood diet that promises to make us lose weight by consuming chocolate and red wine seems exciting at first glance … until we put it into practice and observe the side effects. The explanations of nutritionists.
Popularized by the authors of the book The Sirtfood diet, Aidan Goggins and Glen Matten, the diet consists of consuming almost exclusively foods that act on sirtuins, enzymes which are attributed to slimming, antioxidant and anti-aging properties.
Among the recommended foods are mentioned: kale, red wine, strawberries, onions, soybeans, parsley, virgin olive oil, dark chocolate (85% and more), matcha green tea, buckwheat, turmeric, hazelnuts, lettuce, bird’s eye peppers, apples, dates, walnuts, blueberries, radicchio, capers and coffee. They are nicknamed “superfood”, a term that more and more nutritionists are trying to erase from the collective vocabulary.
Strictly speaking, there are no “forbidden foods”, so it is about limiting the consumption of fat and dairy products to reduce the number of calories ingested. Ideally, we only consume those listed above.
The diet is divided into three phases. A first that lasts three days during which you limit your calorie intake to 1000 calories per day by drinking three homemade green juices, and eating only one “sirtfood” meal. The following four days, we consume a maximum of 1500 calories by contenting ourselves with 2 green juices and 2 “sirtfood” meals.
Then, for two weeks, no calorie restriction, but a limitation to 3 “sirtfood” meals and 1 green juice per day. The authors of “Sirtfood Diet”, a pharmacist and a nutritionist, then suggest starting over to lose more weight, or returning to a normal diet by integrating “sirtfood” foods as much as possible.
Help, I’m hungry!
“This diet will allow you to lose an average of three kilos in seven days, while preserving, and even developing your muscle mass”, promises the duo behind “sirtfood”, with “moderate calorie restriction”.
Yet it is anything but moderate, according to the Quebec nutritionist behind the Science & Fourchette blog, Annie Ferland. She has no doubts about rapid weight loss, but worries about the low calorie intake that dieters get.
“We are talking more about great deprivation. […] No normal person who moves a bit, even without exercising, can live on 1000 calories a day without feeling hungry. Even above 1200 calories a day, it’s dangerous, ”she says, considering that some people need a daily caloric intake of 2500 calories to function normally.
Nutritionist Hubert Cormier even compares Sirtfood to the controversial juice cure, given the number of green juices on the menu. “You might be feeling very hungry, which certainly won’t be a fun time,” he wrote on his blog.
It is also impossible not to lose muscle mass, according to Annie Ferland, since after the water loss, the weight of our body in water, for the first few weeks, the body will inevitably draw on fat and muscle reserves to function. In addition, with a diet so low in calories, it’s a safe bet that we will abandon training sessions for lack of energy.
The creator of Science & Fourchette is also worried about the promise to lose 3 kilos (6.6 pounds) in 7 days and the authors’ suggestion to repeat the diet to achieve its goal. “Everyone has a different metabolism [NDLR: et perd donc du poids à un rythme différent|. Promettre un nombre de livres perdues est très dangereux puisque les gens s’accrochent à ça et peuvent être très déçus du résultat compte tenu de la privation qu’ils se sont infligée.»
Manque de variété
Se limiter à la consommation d’une vingtaine d’aliments, même s’ils sont considérés «sains», n’est pas non plus bénéfique pour la santé. Le guide alimentaire canadien est clair : seule la variété nous permet un apport nutritionnel équilibré en vitamines, lipides, glucides, protéines et minéraux. «Notre corps est un grand orchestre symphonique. Si on arrête le violon, ou l’ingestion d’un type d’aliment, il y a un déséquilibre [NDLR : potentiellement des carences] and we just force, or exhaust our body to make up for the deficit, ”postulates Annie Ferland.
Yoyo effect and long-term consequences
As with all intermittent fasting ketogenic diets, you should expect to regain the weight you lost as soon as you finish the Sirtfood diet, and even gain a few extra pounds.
Why? “Because weight loss has an effect on the basal metabolism. The more restrictive and faster the diet, the slower our normal metabolism will slow down, or in other words the slower our ability to eliminate fat and lose weight naturally without doing anything, explains Annie Ferland. Every diet has a cost on the metabolism. ”
Completing the Sirtfood diet in its entirety also risks emptying the body’s energy reserves, leading it to be in “retention” mode of everything you ingest as soon as you return to a regular diet.
The following are also frequently cited among the consequences of a diet: muscle loss, reduced energy, digestive disorders (heartburn, gastric reflux, gas, stomach or irritable bowel) that follow, but also psychological symptoms such as anxiety, depression, loss of pleasure from food, body dissatisfaction and eating disorders. Consequences that can last a lifetime, warns Annie Ferland.
No human studies
Science has yet to confirm the pros or cons of the Sirtfood Diet, simply because no studies have been done on the effect of sirtuins in humans in the short or long term.
However, work done on mice, yeasts and cell cultures has shown that the level of sirtuins has a positive impact on life expectancy.
But why has Sirtfood supplanted the ketogenic diet and intermittent fasting, yet on everyone’s lips? “It’s just a question of fashion,” says Annie Ferland. It’s very cyclical. Their popularity generally lasts from three to five years, then after that comes another always more “revolutionary”. We hit on carbohydrates, proteins, and now we’re banging on the enzymatic metabolism of sirtuins, and we’re going to start over in a few years. “
According to Hubert Cormier and Ms. Ferland, we should simply put diets aside. As soon as a so-called nutrition expert comes up with “good” and “bad” foods, calorie restriction, or “a diet that is not a diet” without serious scientific studies to back it up, you should look elsewhere.
“Instead, focus on changing your eating habits and your level of physical activity, which are guarantees of success and pleasure,” advises Hubert Cormier.