What Is the Sirtfood Diet? Foods, Rules, Risks & Alternatives

Disclaimer

Educational only. Not medical advice. This page describes the sirtfood diet so you can weigh the claims. It does not recommend starting it. Talk with a qualified clinician before you change how you eat, especially if you are pregnant or breastfeeding, take medication, have a medical condition, or have a history of disordered eating.

Quick facts

What it is	A three-week book plan from UK authors Aidan Goggins and Glen Matten (2016). A branded schedule, not a cuisine.
Core idea	Feature foods the authors call sirtfoods. They say these foods activate sirtuin proteins. Week one is also a green-juice calorie cut.
Risk band	Lifestyle. The foods are ordinary. The opening week is a short, low-calorie schedule, and that week carries the practical risk.
Length	About three weeks: 7 days, then 14, then a looser “keep these foods around” idea.
Often confused with	A juice cleanse, a polyphenol pill, or proof from a celebrity body.
Closer cousins	Mediterranean, DASH, balanced plate. Similar plants. No gene claim, and no 1,000-calorie opener.

The sirtfood diet is a three-week book plan: a short low-calorie week built on green juice, then meals that feature a list of everyday plant foods.

The authors’ pitch is that those foods switch on sirtuins — proteins studied in aging and metabolism labs — and that the switch copies part of what calorie restriction and exercise do. The foods are real. The switch, sold as weight loss you can drink, runs ahead of the evidence. The food list and the calorie schedule are different claims.

How it works

The plan is a schedule plus a shopping highlight list. Grains, soy, coffee, and red wine stay on that list. Week one limits calories, mostly by using juice. The outline below is the public shape of the program, not a menu to copy. Juice amounts and day-by-day meals stay off this page.

The first week

Popular summaries of the 2016 book split the first seven days:

• Days 1–3: About 1,000 calories a day, from three green juices and one meal built around the highlight list.
• Days 4–7: About 1,500 calories a day, from two green juices and two meals.

Promotional copy has called this week a hyper-success phase. The phrase sits on top of a low intake. Some clinics use low-calorie plans with monitoring; a trade book is a different setting. Summaries disagree on small details, such as the juice count on days 4–7. The stable points are the calorie band and the juice-plus-meal pattern.

The next two weeks, and after

The second phase is usually described as 14 days of three highlight-food meals plus one green juice, with snacks in some versions. Calorie numbers for those 14 days vary by summary, so this page does not adopt one. After that, the suggestion is simply to keep the foods and the juice around. A grocery habit does not inherit a gene effect from the opening week.

The green juice

The signature drink is a blend of leafy greens and a few aromatics. Published versions commonly include kale, rocket (arugula), parsley, celery, a green apple, ginger, lemon, and matcha. Amounts differ by reprint and by blog, and they stay off this page on purpose.

That drink is how the first days stay near 1,000 calories and still count as vegetables. It is easy to finish and easy to under-eat, and fiber left in the pulp never reaches the glass. Matcha plus coffee on the food list can stack caffeine. Sleep, reflux, anxiety, and pregnancy limits belong in that stack. This page does not set a caffeine ceiling.

Foods the plan highlights

“Sirtfood” is the authors’ name for foods they picked for polyphenols, plant compounds that also show up in plenty of foods that missed the list. A spot on the list means the book featured that food. It does not make the food a drug, and foods left off are not harmful by omission.

These are common public versions of the highlight list, not a prescription:

• Kale, rocket (arugula), parsley, lovage, and red chicory
• Onions, celery, and bird’s eye chili
• Strawberries, blueberries, and Medjool dates
• Walnuts, soy foods, and buckwheat
• Extra-virgin olive oil, turmeric as a cooking spice, and capers
• Dark chocolate, often described at a high cocoa percent
• Coffee, matcha or other green tea, and red wine

Meals in coverage of the book are ordinary plates, such as a salad or curry, often with chicken beside the plants. Soy and buckwheat stay available. That does not change a 1,000-calorie day. A packaged bar using the name is a product, not proof of sirtuin activation, and turmeric in food is a spice rather than a supplement dose.

Evidence snapshot

Sirtuins are real proteins. Humans have seven, SIRT1 through SIRT7, studied mostly in cells, yeast, worms, and mice for roles in stress and metabolism. Calorie restriction and some plant compounds, including resveratrol, have been tested as possible activators in those settings. A lab clue is not a result you can assign to a branded juice.

The book then claims that culinary amounts of the list raise sirtuin activity in a person, that this stands in for exercise, and that the three-week plan beats an ordinary lower-calorie diet. No published randomized human trial of this named diet is available to cite. This page will not invent one.

About 7 pounds in seven days is the authors’ figure from a small pilot, often described as roughly 40 people on the first week. There is no comparison group at the same calories, and it was not a peer-reviewed trial. Energy, skin, sleep, and muscle claims come from that same unpublished note.

A week near 1,000 to 1,500 calories can drop the scale through water, glycogen, and less food in the gut, on many menus with no special list. Eating very little can also cost muscle, which clashes with marketing that says muscle is spared. That is not a sirtuin result, and it does not describe the months afterward.

Press later attached the diet to celebrity weight loss. In a 2021 British Vogue interview, Adele said she had not followed the sirtfood diet. That retires a famous anecdote. It is not a trial. The authors’ nickname for SIRT1, “skinny gene,” is a slogan for one protein among seven, not a switch that kale and cocoa flip.

Potential benefits

These are overlaps with ordinary eating. They are not promised results, and they do not require the first week.

The highlight foods are ordinary. Leafy greens, berries, onions, herbs, soy, walnuts, olive oil, and buckwheat already fit varied diets. Cooking more of them, and fewer sugary ultra-processed snacks, matches guidance that does not mention sirtuins. Mediterranean-style eating and a balanced plate already point that way.

Fewer groups are dropped than on many named diets. Soy, buckwheat, and coffee can stay, which makes later cooking easier. Days 1–3 are still three juices and one meal. A lower scale that week comes from less glycogen and water, not from a sirtuin effect, and it is not fat lost, muscle kept, or a result that lasts.

Risks & who should avoid

The Lifestyle band files this pattern with everyday eating styles because the highlight foods are normal foods. The first week is still a sharp cut. Explain ≠ endorse.

Hunger and a low intake. About 1,000 calories, then about 1,500, is a large drop for many adults. Headache, irritability, fatigue, feeling cold, constipation, dizziness, and poor concentration are common. The numbers are a poor fit if you already eat sparingly, are ill, or train hard. Repeating the week when the scale bounces is a crash cycle.

Juice in place of meals. A glass skips much of the chewing that makes a meal feel finished. Apple in the drink is still liquid sugar, which matters for teeth and for hunger an hour later. Daily kale and parsley also shift vitamin K intake. People on warfarin need that intake steady, so the prescriber should hear about a new juice habit before day one.

Caffeine, wine, and a health halo. Matcha plus coffee can add up. Red wine is on many published lists and is irrelevant to any benefit this page can support. Alcohol is a poor fit in pregnancy, with many medicines, with liver disease, and with a history of alcohol problems. Dark chocolate, dates, olive oil, and walnuts are energy-dense; calling them activators does not change that. Soy and walnuts are also allergens. Chest pain, fainting, a sudden weight change, or a return of disordered eating needs a clinician, not another juice.

Who should talk with a clinician or a registered dietitian nutritionist (RDN) before using this pattern

• Pregnancy or breastfeeding, and anyone planning meals for a child or teenager
• A history of disordered eating, or a habit of restarting short crash weeks
• Diabetes treated with insulin or other glucose-lowering medicines
• Blood-pressure medicines, warfarin, or another medicine where vitamin K intake matters
• Kidney disease, or a diet that already limits potassium
• Underweight, a poor appetite, recovery from illness, or heavy training loads
• Anyone hoping a book phase will treat a diagnosed disease

This page does not hand out a calorie target to follow.

Safer alternatives

The plants on the sirtfood list already fit patterns that skip the 1,000-calorie opening and the gene nickname.

• Balanced plate — vegetables, protein, and fiber-rich carbohydrates, with fats such as olive oil or nuts. No juice quota and no three-day crash.
• Mediterranean — vegetables, fruit, legumes, whole grains, nuts, olive oil, and often fish. The same plants show up as food, not as activators.
• DASH — a lifestyle-band pattern often used in blood-pressure education. Produce, nuts, and beans overlap. The lesson is the weekly plate, not a juice phase.

A green juice beside ordinary meals is only a drink. If juicing pushes vegetables off the plate, keep the plate. Symptoms, labs, and medicines belong with a clinician or RDN.

FAQ

What is the sirtfood diet?

A three-week plan from the 2016 book by Aidan Goggins and Glen Matten. Week one is about 1,000 then 1,500 calories, built on green juice and a few meals. Later days feature everyday plant foods the authors say activate sirtuins. That activation claim is not an established human result.

Which foods are called sirtfoods?

Public lists usually include kale, rocket, parsley, onions, berries, dates, walnuts, soy, buckwheat, olive oil, turmeric, capers, dark chocolate, coffee, matcha, and red wine. Summaries shuffle the edges. Foods left off the list are not banned.

Does it switch on a skinny gene?

Human evidence is lacking. “Skinny gene” is a nickname for SIRT1, one of seven sirtuin proteins. Lab research does not show that this plan changes body fat through that protein.

Why does the scale drop in week one?

The week is a low-calorie schedule, so water, glycogen, and less food in the gut move the number. About 7 pounds in seven days is the authors’ uncontrolled pilot account, not a published trial, and it does not describe the next month.

Is red wine required?

No. Skip wine in pregnancy, with conflicting medicines, with liver disease, and if you do not drink. Greens, berries, and olive oil fit a balanced plate without alcohol. This page has no juice recipe to follow.

How is it different from Mediterranean eating?

Both can include olive oil, greens, berries, onions, herbs, nuts, and beans or soy. A Mediterranean-style pattern keeps grains, legumes, and often fish, without a 1,000-calorie opener or a fat-loss gene. DASH is the other close sibling, taught more often around blood pressure.

Who should skip this plan?

Skip the first week in pregnancy, while breastfeeding, under 18, if you are underweight, or during treatment for an eating disorder. Ask a clinician first if you use insulin or other diabetes medicines, blood-pressure medicines, or warfarin, and if you have kidney disease. A food list does not treat a diagnosed disease.

Related

• Balanced plate — meal building without a juice week or a gene claim
• Mediterranean diet — lifestyle-band sibling that already uses many of the same plants
• DASH diet — lifestyle-band sibling often taught alongside blood-pressure care
• Diets directory — A–Z encyclopedia hub; this entry’s path is /diets/sirtfood/

Sources

[SOURCES TBD — no fabricated trials. The pilot weight figure is the authors’ unpublished account, not a peer-reviewed result. Celebrity denial: British Vogue, 2021. Calorie bands follow widely repeated summaries of the 2016 book.]

Last reviewed

2026-09-24. Draft for copy review. Not a clinical review and not published.