Sirtfood Diet: Everything you need to know about Adele’s weight loss method

The Sirtfood Diet is thought to be behind Adele's incredible weight loss.
  • We earn a commission for products purchased through some links in this article.
  • The Sirtfood Diet is about using ‘wonderfoods’ to ‘turbocharge’ your body to not only increase weight loss but to improve your overall health in the long-term too.

    The Sirtfood Diet plan has been championed by celebrities and sports personalities alike including Olympic gold medalist Ben Ainslie and English rugby player James Haskell. It is also rumoured to be the diet plan behind Adele’s weight loss, although the superstar singer has never spoken publicly to confirm this.

    Known to be one of the diets that work fast, one of the best things about the Sirtfood Diet is that you don’t have to ban treats such as chocolate or wine but you can still see results.

    What is The Sirtfood Diet?

    “The Sirtfood Diet was developed in 2015 by two nutritionists – Aidan Goggins and Glen Matten,” explains Dr Deborah Lee from Dr Fox Online Pharmacy. Aidan and Glen have released a book on The Sirtfood Diet.

    “The diet relies on eating specific foods (called Sirtfoods) that stimulate the production of proteins called sirtuins (sirts) in the body. Sirt stands for Silent Information Regulator Protein.”

    The science behind the diet is all based around the power these Sirtfoods have on the sirt proteins.

    “There are seven sirt proteins (S1-7), and each has specific metabolic functions,” says Dr Lee.

    “S1 is associated with fat breakdown and weight loss – this is why you may have heard of The Sirtfood Diet as the diet which activates the ‘skinny gene’ pathways in the body.”

    Apple with tape measure

    Apples are a type of Sirtfood. (Credit: Getty)

    These “skinny gene” pathways are the same ones more commonly activated by fasting and exercise. They help the body to burn fat, increase muscle mass and improve your health. Countries where people already consume a vast number of Sirtfoods as part of their traditional diet, including Japan and Italy, are both regularly ranked among the healthiest countries in the world.

    ‘The authors of The Sirtfood Diet believe that eating Sirtfoods not only activates sirt genes, but they also help to stabilise blood sugars and fight inflammation,’ says Dr Lee.

    ‘Sirtuins have been identified as having an important role in anti-ageing. Some scientists believe that increasing the dietary intake of sirtuins, and taking more physical exercise, may extend the human lifespan.’

    What do you eat on The Sirtfood Diet?

    Top Sirtfoods include:

    • Apples
    • Strawberries
    • Grapes
    • Soybeans
    • Tofu
    • Shallots
    • Liquorice
    • Olive oil
    • Kale
    • Red and White wine
    • Onions
    • Buckwheat
    • Blueberries
    • Matcha green tea
    • Dark chocolate (85% cocoa)
    • Parsley
    • Walnuts
    • Birds-eye chillies
    • Capers
    • Coffee
    • Lovage
    • Green Tea
    • Medjool dates
    • Turmeric

    There are plenty of foods to eat on The Sirtfood Diet, so you won’t feel that you are missing out. 

    ‘Sirtfoods comprise a range of specific sirt-rich foods,’ says Dr Lee. ‘Examples include resveratrol, which is found in grapes and red wine. Quercetin, found in buckwheat, onions, green vegetables, and berries. Plus, omega-3 fatty acids – found in oily fish, nuts, and seeds.’

    Grapes and wine

    Grapes and wine are a key part of The Sirtfood Diet. (Credit: Getty)

    The authors say processed and high sugar foods should be avoided. ‘Medjool dates are Sirtfoods, but all dried fruits are high in sugar, so don’t overdo it,’ warns Dr Lee.

    ‘On The Sirtfood Diet, high-carb foods, such as pasta, potatoes, beans, and legumes are to be avoided as they are not Sirtfoods. When following the diet, you should fill up on green vegetables instead.’

    Green vegetables in a wire basket

    Fill up on green veg. (Credit: Getty)

    And that’s not all. ‘Dairy foods, such as milk, eggs, and butter are permitted, but stick to the quantities recommended in the recipes,’ says Dr Lee. 

    The biggest pro is that red wine, dark chocolate and coffee are actively encouraged on this diet – and that isn’t something you often hear.

    ‘And, yes, you can drink 2-3 glasses of red wine per week!’ says Dr Lee.

    Although, of course drinking a kale smoothie followed by a whole bar of Green and Blacks isn’t going to see you dropping the pounds. Everything in moderation.

    Aidan and Glen say that participants rarely feel hungry – which means it’s good for anyone who can’t get through one day of a normal cleanse without feeling like they are going to faint unless they eat a Big Mac immediately.

    Salmon is a Sirtfood

    Go for oily fish, like salmon, over red meat. (Credit: Getty)

    Can you eat meat on The Sirtfood Diet?

    ‘You can eat meat on The Sirtfood Diet,’ confirms Dr Lee. The maximum permitted is 750g red meat three times a week. But eating meat is optional, so The Sirtfood Diet can be vegetarian-friendly and can also be followed by anyone on a vegan diet.

    ‘Meat is a good source of leucine, an amino acid that enhances the action of S1,’ says Dr Lee. ‘But avoid processed meats such as bacon, salami, and ham as these are processed foods. Fish and poultry can be eaten as often as you like. Oily fish is recommended.’

    However, one thing to note is that the rules concerning meat don’t seem to be directly related to activating the sirt genes.

    ‘None of this has anything to do with the sirtuin genes based on the research available to date,’ says Alex Ruani, UCL doctoral researcher and chief science educator at The Health Sciences Academy.

    Can you drink coffee on The Sirtfood Diet?

    Yes. You can drink all fluids, including coffee, freely throughout all the stages of The Sirtfood Diet. Coffee is listed within the top 20 Sirtfoods.

    Coffee is allowed on The Sirtfood Diet

    Opt for coffee without milk. (Credit: Getty)

    If you do drink coffee, just don’t add too much milk. ‘Coffee should be taken black as milk can interfere with the absorption of some of the nutrients in the diet,’ adds Dr Lee. ‘Drinking coffee can help you burn an extra 100 calories per day.’

    You may, however, wish to go easy on too many caffeinated drinks, as too much caffeine can lead to palpitations, high blood pressure and nausea.

    How to follow The Sirtfood Diet

    The Sirtfood Diet plan is based on two stages. 

    Stage one is an intensive seven-day program designed to kick-start your intense weight loss. Then stage two is about upping the quantity of Sirtfood-rich produce in your everyday meals to maintain weight loss.

    Unlike many other short-term yo-yo diets, The Sirtfood Diet plan includes meals and advice on how to keep off the weight you lose in the first week by continuing to integrate Sirtfoods as part of a healthy and balanced diet.

    Glass of green juice

    Green juice is key during both Stages of The Sirtfood Diet. (Credit: Getty)

    Stage One: Days 1-7

    For the first three days dieters drink two green juices a day – including kale, celery, rocket, parsley, lemon and green tea – and eat one meal.

    For example, the meal can be something like turkey escalope with sage, chicken and kale curry and prawn stir-fry with buckwheat noodles or sesame-glazed tofu if you’re vegetarian. All made up of high Sirtfood ingredients.

    You can also have 15-20g of dark chocolate after your meal if you have a sweet tooth.

    But no alcohol is allowed during these three days,’ adds Dr Lee.

    For the second half of your first week (Days 4-7), you can have two juices and two meals a day, with similar ingredients to the first three days.

    Stage Two: Days 8-14

    After the initial stage of fasting the focus shifts to eating ‘normally’ again, but upping your intake of the healthy Sirtfoods. ‘This involves three sirt meals per day, one green juice and one to two sirt snacks,’ says Dr Lee.

    Spoonful of blueberries

    Blueberries make an ideal Sirtfood snack. (Credit: Getty)

    Sirt snacks include:

    • A cup of green tea
    • 10 red grapes
    • An apple
    • 10g cocoa
    • 6 olives
    • 15 blackberries
    • 50g pomegranate seeds
    • 80g blueberries
    • 6 squares of dark chocolate containing at least 85% cocoa solid

    Once you’ve completed both stages, you can choose what to do next. ‘You can either repeat stage one, or repeat stage two, or just continue to eat regular sirt meals,’ says Dr Lee. 

    ‘The idea going forward is not counting calories, but to stick to a healthy diet full of Sirtfoods. You should have one glass of green juice every day and continue to drink tea and coffee. You can find lots of recipes in the Sirtfood Diet Book. Red and white wine are also permitted, but you shouldn’t eat any food after 7pm.’

    Does The Sirtfood Diet work?

    The Sirtfood Diet plan works in two ways. The first is that Sirtfoods stimulate sirtuin genes, which are said to influence the body’s ability to burn fat and boost the metabolic system. 

    ‘There is mass evidence showing the benefits of bioactive compounds in plant foods, including those recommended in the diet. This is undisputable,’ says Alex.

    ‘Bioactive compounds, like resveratrol from red grapes and epigallocatechin gallate from green tea, provide an additional physiological benefit beyond that of meeting basic nutritional needs, in many instances by helping modulate sirtuin genes.’

     The second way the Sirtfood Diet works is by restricting calories.

    Woman checking calories of meal via an app

    Restricting calories is a big part of the plan. (Credit: Getty)

    ‘If you restrict calories, whether those calories come from Sirtfoods or not, you’ll lose weight. The laws of thermodynamics are inescapable,’ says Alex. ‘Eating fewer calories than you expend does lead to weight loss. Full stop.’

    Due to this, whether you choose to eat Sirtfoods or not, doesn’t really matter.

    ‘When we take in fewer calories than we use or excrete, we lose weight,’ says Alex. ‘And it doesn’t matter if those calories come from junk food or from whole fresh foods, from Sirtfood choices or Keto choices, or if they are eaten at different times of the day.

    ‘Of course, opting for greens and berries instead of fries and cake helps with our overall health and wellbeing. Caloric restriction without malnutrition, junk food, or alcohol seems like the least damaging option.’

    Overall, there hasn’t been enough research done to determine whether The Sirtfood Diet really works yet. 

    ‘To date, there is no published evidence that The Sirtfood Diet plan is any better than any other diet at helping you lose weight,’ adds Dr Lee.

    How do I start The Sirtfood Diet?

    The initial stage of The Sirtfood Diet involves juicing and fasting only. This seems good for those who might want to shift a few pounds quickly, but can be hard when it comes to preparation, so it’s worth planning ahead.

    Dr Lee says:

    • Organisation is key. “You will need to purchase the food ingredients for your first few days on the diet in advance.”
    • Make sure you have a proper juicer to make the all-important green juice. “A blender or a NutriBullet won’t do – they just produce a green sludge.”  
    • Choose your Sirtfood meals. “There are many recipes to choose from in The Sirtfood Diet book.”
    • Start at the right time for you. “Think ahead about what you have planned and how you can deal with this way of eating.”

    Yet, even with forward planning, The Sirtfood Diet can be difficult to start.

    ‘From a behavioural psychology point of view, it’s quite hard to implement all of its recommendations at once,’ says Alex.

    ‘It requires a lot of preparation, cooking skills, getting the right equipment (like a juicer instead of a blender), and making radical changes in the way we eat and when or how we eat. The sheer number of items to prepare may be off-putting even for someone who has excellent planning or cooking skills.’

    Juicer with fresh produce

    You’ll need to invest in a juicer. (Credit: Getty)

    Plus, limiting the number of calories you have can sound extreme for some people. So choose a time to start that doesn’t clash with something in your life that may derail you, like a holiday or big event.

    ‘The first week requires extreme caloric restriction, so it’s not an easy start for most people,’ says Alex.

    Days one to three are most intensive with your calorie intake limited to 1,000 – combined of three juices and one meal.

    Days four to seven are a little more lenient with a calorie maximum of 1,500 calories per day.

    Aidan and Glen say that in order to combat the fasting period, don’t focus on how much weight you are losing, rather look at the health impact on your tone and how your clothes fit, not to mention how radiant your skin will look.

    They advise fasters to spread the juices out throughout the day rather than having them too close together. Plus, consume the juices at least an hour or two before and after meals.

    woman doing laces ready for exercise

    Be wary of doing too much exercise when fasting. (Credit: Getty)

    You also need to be wary about exercising during the first stage when you are not consuming many calories.

    ‘Although the diet promises losing fat while maintaining muscle mass, when you limit your calories severely, you will inevitably lose some muscle mass,’ says Alex. ‘And even more so if you exercise, as you’ll be more rapidly depleting glycogen stores in muscle, so the body starts breaking down muscle protein for fuel.’

    Is the diet safe, healthy and sustainable?

    The Sirtfood Diet is still relatively new, which means scientific evidence is still unclear when it comes to certain aspects of it.

    ‘It’s not possible to comment on the safety of The Sirtfood Diet, as there are no published studies about its long-term safety,’ says Dr Lee. ‘Plus, while there is some medical evidence that restricting calories could be associated with longevity, we do not know this for sure.’

    woman at dentist with toothache

    The Sirtfood Diet may be problematic for teeth. (Credit: Getty)

    There are definitely some aspects of the diet which are not particularly healthy, though.

    ‘The calorie restriction is severe and may lead to symptoms such as headaches, feeling cold, constipation and difficulty sleeping,’ says Dr Lee. ‘Some people have commented that the diet may not contain adequate amounts of protein. And drinking copious amounts of fruit juice damages tooth enamel and can be dangerous for your teeth.

    However, many aspects of The Sirtfood Diet plan are healthy.

    ‘We all eat too much and have too large portion sizes. If this diet helps people choose healthy food, and eat little and often, this has to be a good thing,’ says Dr Lee. ‘The diet is creative, with interesting recipes and offers a wide choice of foods.’

    And that’s not all. ‘The recommended foods are fresh with large quantities of antioxidants, vitamins, and minerals,’ says Dr Lee. ‘And the diet is also high in unsaturated fats, and dietary fibre.’

    We’ll have to wait and see if Sirtfood remains Adele’s sustainable weight-loss trick. But she’s not the only celebrity raving about the diet.

    Model Jodie Kidd says; ‘People keep asking me my secret to looking great. The answer is Aidan and Glen’s Sirtfood Diet. Since following it, I feel unstoppable.’

    Lorraine Pascale, TV presenter, said; ‘A non-faddy diet that offers incredible health benefits and weight loss. Aidan and Glen show how everyone can reap the benefits of The Sirtfood Diet through eating delicious food. I’m a huge fan!’

    Ben Ainslie says; ‘I’m healthier, more alert, and in top physical condition. Sirtfoods are key for me reaching new peaks in performance to face the upcoming challenges.’

    Yet whether the diet is sustainable or not for you, really depends on your personal circumstances. 

    ‘There’s no doubt that losing weight and keeping it off is imperative for optimal health. So, in the short term, to some extent, it doesn’t matter how you do it, so long as the diet works for you, and you lose the weight,’ says Dr Lee. 

    ‘However, in the longer term, you need to change your eating patterns forever, and it’s unlikely you could stick to The Sirtfood Diet indefinitely. A more rational approach would be just to add Sirtfoods to your daily meals.’

    The Sirtfood Diet is not recommended for pregnant women or those trying to conceive. It’s also not suitable for people with diabetes, or some other chronic long-term medical conditions. Always check with your doctor before you start a new diet regime.