Sirtfood diet: can you really lose 3 kilos in a week?


 The Sirtfood diet promises rapid weight loss through the ingestion of foods rich in sirtuins, enzymatic proteins that would help burn fat. How exactly does this diet work? What is it really worth? Are there any risks? Explanations with Dr. Arnaud Cocaul, the nutritionist doctor.

What is the Sirtfood diet?

The Sirtfood Diet, or Sirtfood Diet in English, consists of consuming sirtuin-activating foods, enzymatic proteins "that increase the body's ability to burn fat," reads the book by the two creators of the program. They claim that "by combining a diet rich in sirtfoods", also called "superfoods", "with moderate calorie restriction", this diet allows "to lose an average of three kilos in seven days, while preserving, and even developing your muscle mass". It would also have an anti-aging effect and reduce the risk of chronic diseases.

Sirtfood diet: can you really lose 3 kilos in a week?

These promises are based on a study published in 2003 in the journal Nature1, which showed that resveratrol, an antioxidant found in grapes and thus wine, had the ability to activate sirtuins in a type of yeast (Saccharomyces cerevisiae). Results: Resveratrol was able to mimic calorie restriction and thus extend the life of the yeast.

The inventors of the Sirtfood diet also relied on their own pilot test. In their book, they explain that they tested it in the London fitness and fitness center KX. For seven days, KX members had to follow the diet "carefully crafted from sirtuin-activating foods" and with "moderate" calorie restriction for the first three days, while their progression (in terms of weight, percentage of fat and muscle mass, sugar levels, triglycerides, and cholesterol) was measured. Verdict: the 39 people who followed the diet to the end saw rapid weight loss (3 kilos in a week on average), the development of their muscle mass, a hunger "rarely" present, and "an increased sense of vitality and well-being".

What foods are rich in sirtuins?

A list of 20 superfoods is touted by the Sirtfood diet. We find as follows:

  • kale,
  • rocket,
  • lovage,
  • onions,
  • red chicory,
  • soybeans, 
  • buckwheat,
  • celery,
  • parsley,
  • Medjool dates,
  • strawberries,
  • nuts,
  • capers,
  • turmeric,
  • extra virgin olive oil,
  • bird's eye pepper,
  • dark chocolate,
  • red wine,
  • matcha green tea,
  • coffee.
  • The Sirtfood diet in practice

How to apply the Sirtfood diet in practice? It is based on two phases:

  • Phase 1 (7 days): for the first three days, the daily calorie intake is limited to 1000 calories, with 3 green juices and a full meal based on superfoods per day. For the next four days, the daily calorie intake is limited to 1500 calories per day, with two green juices and two superfood meals per day.
  • Phase 2 (14 days): this "maintenance" phase is based on the consumption of 3 meals rich in sirtuin-activating foods and one green juice per day.
  • Phase 3: The post-diet may seem difficult to negotiate as in all diets, but the founders of the method ensure that if we continue to consume the foods most likely to raise our sirtuin levels and drink green juice every day, weight loss stabilizes. Or how to adopt the Sirtfood lifestyle and stay slim all year round.

The benefits of the 'Sirtfood' diet

The superfoods that make up the diet all have their health benefits. Integrating them into your diet can not be a bad idea because they are full of benefits.

  • Dark chocolate rich in cocoa is full of elements with strong antioxidant power such as polyphenols, catechins, and flavanols.
  • Red wine is very rich in resveratrol, an antioxidant that helps fight free radicals and inflammation.
  • Turmeric is known for its anti-inflammatory and antioxidant properties, for its ability to increase cognitive functions and also to thin the blood.
  • Blueberry is one of the richest berries in antioxidants, fiber, and vitamin C. It protects against heart disease, vascular disease, Alzheimer's disease, diabetes, and facilitates all slimming diets by regulating insulin production.
  • Matcha is rich in catechins, antioxidants that protect the liver and heart, improve brain function, and promote weight loss.
Sirtfood foods are both nutritious and low in calories, and consuming them on a regular basis is naturally a very good thing, provided they are whole and, if possible, raw.

Drinking the juice of a fruit or vegetable does not bring a quarter of its benefits. The fiber is degraded as soon as it is passed through the blender, and the superfood you held in your hands a few minutes ago becomes nothing more than a sugar juice!

And if sort food foods are the basis of the nuggets of benefits, the Sirtfood diet in itself brings little benefit, both on health and on weight loss.

Is this diet really effective for weight loss?

If the benefits of these ingredients are indisputable for health, what about the slimming virtues of the Sirtfood method?

To begin with, the weight loss observed in the first days of the first phase is mainly due to a loss of water and muscle, caused by the elimination of carbohydrates and proteins. And if you've ever tested a few diets, you must have noticed that this is what we always observe at the beginning: it goes down quickly!

Then, who says rapid weight loss says even more dazzling weight recovery. The energy intake of these three weeks of a dry diet is so low that it cannot be made to last more than a few weeks. Then you have to reintegrate the 'normal' food, and that's the drama. We realize that to stabilize weight loss, we must continue to follow the diet. So we refeed normally, and we regain more weight than we had lost. The yo-yo effect, very useful for bodybuilders who want to gain a lot of mass after a dry diet, is the worst enemy of all candidates for thinness.

Finally, the risks of deficiencies and loss of muscle tissue are real. This diet does not include enough protein sources to fuel the muscles. And muscle mass, even if you don't want to develop it, is the engine of metabolism, the place where fat is most likely to be burned. With a diet of this kind, you risk losing more muscle than fat, although the scale gives you encouraging news. Not to mention that the handling of sirtuins has been studied on animals, but no research has yet been done on humans.

Sample menu

Breakfast: a soy yogurt with red fruits, chopped nuts, and dark chocolate, or a bacon omelet, red chicory, and parsley.

Lunch: a Sirtfood salad with arugula, endive leaves, slices of smoked salmon (100g), avocado, celery, red onions, nuts, capers, a large chopped Medjool date, extra virgin olive oil, lemon juice, and parsley.

Dinner: shrimp stir-fry (150g) with kale, buckwheat noodles, tamari sauce, extra virgin olive oil, garlic, bird's eye pepper, ginger, red onions, celery, and green beans.

Green juice: kale (75g), arugula (30g), flat parsley (5g), two to three branches of celery with leaves (150g), half a green apple, fresh ginger (1 to 2.5cm), the juice of half a lemon, half a teaspoon of matcha tea powder.

Our opinion 

If the marketing argument 'chocolate and red wine' hits the mark among gourmets, the Sift Food Diet remains a low-calorie diet, and that can be considered restrictive even if it is obviously not sold as such. Ultra-targeted on certain foods, it does not rely on variety, yet essential for optimal intake of vitamins and minerals and... to avoid frustration. Not to mention that chocolate, red wine, and olive oil have never been banned in many classic diets. On the contrary, they participate, in particular, in the famous Mediterranean diet, considered one of the best diets in the world for line and health.