sirtfood diet

What is the Sirtfood Diet and does it work?

Written by: Kelley R. Hill, MSN, RN-BC

In a Nutshell

  • The Sirtfood Diet is an alternative to intermittent fasting with the same benefits
  • Combines sirtfoods and significant calorie restriction
  • The signature green juice is an essential part of the diet, and is encouraged as part of your regular diet once the Sirtfood Diet is completed

Fasting has become a very popular dieting approach to weight loss. When we fast, our body activates a group of proteins called sirtuins (SIRTs or “skinny genes”) that have been shown to regulate a variety of functions, including metabolism, inflammation, and lifespan. SIRTs are believed to aid in producing desired changes such as weight loss and improved resistance to disease.

If not done correctly, however, fasting can lead to hunger, irritability, fatigue, loss of muscle, sleep disruptions, loss of mental focus, and other health complications.

The Sirtfood Diet claims to solve the fasting problem. Sirtfoods are a “newly discovered” group of foods, ranging from chocolate and red wine to garlic and walnuts, that are particularly rich in special nutrients that help us activate the same skinny genes in our bodies that fasting triggers… Without fasting. Certain natural plant compounds may be able to increase sirtuin protein levels in the body, and foods containing them are “sirtfoods.”

The Sirtfood Diet claims that following the diet will lead to rapid weight loss, while maintaining muscle mass and protecting you from chronic disease, and still giving you “incredible energy and glowing health.”

Sirtfood Diet Foods

Top 20 sirtfoods in the Sirtfood Diet:

  • Arugula
  • Bird’s eye chilis
  • Blueberries
  • Buckwheat
  • Capers
  • Coffee
  • Dark chocolate (85% or higher cocoa)
  • Extra virgin olive oil
  • Kale
  • Lovage
  • Matcha green tea
  • Medjool dates
  • Onions
  • Parsley
  • Red chicory
  • Red wine
  • Soy
  • Strawberries
  • Turmeric
  • Walnuts

The majority of sirtfoods have proven health benefits such as lowering blood pressure, risk for heart disease, stroke, and diabetes, and fighting inflammation. The evidence on their ability to increase sirtuin protein levels is limited, however, and presently is it not possible to determine the effects of increased sirtuin levels in humans.

Sirtfood Phases

The diet is completed in two phases and lasts for three weeks. The Sirtfood Diet book must be purchased to follow the diet, as the specific meal recipes for the two phases are only found in the book.

Phase One

  • Lasts 7 days
    • First three days, there is a 1,000-calorie restriction
      • Drink three green juices per day plus one meal
    • Days 4-7, caloric intake is increased to 1,500
      • Drink two green juices per day plus two meals

Phase Two

  • Lasts 2 weeks
    • No specific calorie limit
    • Drink one green juice per day plus three meals

After the Diet

  • Repeat the two phases as often as desired for weight loss
  • Continue to consume as many sirtfoods as possible as part of your regular diet
  • Continue drinking the green juice daily

You make the green juice yourself. You need a juicer (not a blender) and a kitchen scale. The green juice recipe is available online.

Science & Experts

There is no science backing the claims of the diet’s creators, and no convincing evidence that the Sirtfood Diet is any more effective in achieving weight loss than any other calorie-restricted diet. The foods have healthful properties, to be sure, and are good food choices, though there are not any long-term human studies that show eating a diet rich in sirtfoods has any health benefits.

Experts assert that the Sirtfood Diet is unnecessarily restrictive, not nutritionally balanced, and offers no clear, unique health benefits over any other type of diet. There is great concern over the first three day 1,000-calorie restriction, which does not meet minimum caloric intake recommendations and should only be done under the supervision of a physician. It may not be fasting, but it is famine.

Experts also point out that the diet requires drinking a lot of green juice and while juices can be good sources of vitamins and minerals, they are high in sugar and contain none of the healthy fiber that whole fruits and vegetables offer. Because the diet is so limited in both calories and food choices, it is also likely lacking essential protein and nutrients – especially during Phase One. This, coupled with the high initials cost (juicer, scale, book, rare and expensive ingredients), may make the diet impossible for many.


You should not participate in the Sirtfood Diet if you have diabetes, as calorie restriction and drinking mostly juice can cause dangerous changes in blood sugar levels.

For the otherwise healthy adult, there are no real safety concerns and serious health complications are unlikely given that the diet is only three weeks. Even a healthy person will no doubt experience HUNGER, however, with such low caloric intake and no fiber (a nutrient that helps you feel full).

Phase One may produce symptoms such as lightheadedness, difficulty concentrating, fatigue, nausea, headaches, and irritability due to the low caloric intake.

You should always consult with your physician, and ideally a nutritionist or registered dietician (RD), before radically changing your diet or eating habits. Especially if you have existing health conditions, are on prescription medications, or are pregnant or breastfeeding.


Theory and health claims are based on very preliminary scientific evidence, predominantly from animal studies, and any calorie-restricted diet plus exercise – with or without the inclusion of sirtfoods – is likely to result in rapid and significant weight loss.


The Sirtfood Diet has healthy food but not healthy eating patterns. Adding sirtfoods to your diet may be a good idea for their proven health benefits, though questions remain about its sustainable and effectiveness for weight loss.


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