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What is the Sirtfood diet?
Launched originally in 2016, the Sirtfood diet remains a hot topic and involves followers adopting a diet rich in ‘sirtfoods’. According to the diet's founders, these special foods work by activating specific proteins in the body called sirtuins. Sirtuins are believed to protect cells in the body from dying when they are under stress and are thought to regulate inflammation, metabolism and the aging process. It's thought that sirtuins influence the body’s ability to burn fat and boost metabolism, resulting in a seven pound weight loss a week while maintaining muscle. However, some experts believe this is unlikely to be solely fat loss, but will instead reflect changes in glycogen stores from skeletal muscle and the liver.
So what are these magical ‘sirtfoods’? The ten most common include:
- Green tea
- Dark chocolate (that is at least 85 per cent cocoa)
- Citrus fruits
- Red wine
The diet is divided into two phases; the initial phase lasts one week and involves restricting calories to 1000kcal for three days, consuming three sirtfood green juices and one meal rich in sirtfoods each day. The juices include kale, celery, rocket, parsley, green tea and lemon. Meals include turkey escalope with sage, capers and parsley, chicken and kale curry and prawn stir-fry with buckwheat noodles. From days four to seven, energy intakes are increased to 1500kcal comprising of two sirtfood green juices and two sirtfood-rich meals a day.
Although the diet promotes healthy foods, it's restrictive in both your food choices and daily calories, especially during the initial stages. It also involves drinking juice, with the amounts suggested during phase one exceeding the current daily guidelines.
The second phase is known as the maintenance phase which lasts 14 days where steady weight loss occurs. The authors believe it’s a sustainable and realistic way to lose weight. However, focusing on weight loss is not what the diet is all about – it’s designed to be about eating the best foods nature has to offer. Long term they recommend eating three balanced sirtfood rich meals a day along with one sirtfood green juice.
Dietitian Emer Delaney says:
‘At first glance, this is not a diet I would advise for my clients. Aiming to have 1000kcal for three consecutive days is extremely difficult and I believe the majority of people would be unable to achieve it. Looking at the list of foods, you can see they are the sort of items that often appear on a ‘healthy food list’, however it would be better to encourage these as part of a healthy balanced diet. Having a glass of red wine or a small amount of chocolate occasionally won’t do us any harm - I wouldn’t recommend them on a daily basis. We should also be eating a mixture of different fruits and vegetables and not just those on the list.
‘In terms of weight loss and boosting metabolism, people may have experienced a seven pound weight loss on the scales, but in my experience this will be fluid. Burning and losing fat takes time so it is extremely unlikely this weight loss is a loss of fat. I would be very cautious of any diet that recommends fast and sudden weight loss as this simply isn’t achievable and will more than likely be a loss of fluid. As soon as people return to their regular eating habits, they will regain the weight. Slow and steady weight loss is the key and for this we need to restrict calories and increase our activity levels. Eating balanced regular meals made up of low GI foods, lean protein, fruit and vegetables and keeping well hydrated is the safest way to lose weight.’
Please note: if you're considering attempting any form of diet, please consult your GP first to ensure you can do so without risk to health.
Weight loss and good health can be achieved by following a healthy, balanced diet. Our nutritionist approved plan helps you find your perfect portion size, guideline daily amounts and nutritionally balanced breakfasts, lunches, dinners and snacks:
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Want facts and information on other diets? Read more from our health editor and nutritionist on other popular weight loss plans:
This page was last reviewed on 19th February 2020 by Kerry Torrens.
Emer Delaney BSc (Hons), RD has an honours degree in Human Nutrition and Dietetics from the University of Ulster. She has worked as a dietitian in some of London's top teaching hospitals and is currently based in Chelsea.
Kerry Torrens BSc. (Hons) PgCert MBANT is a Registered Nutritionist with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food.
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