It’s the hot new diet of 2016 and it’s hardly surprising – you’re positively encouraged to eat dark chocolate and drink red wine! So what’s the story?

The Sirtfood diet was invented by nutritionists Aidan Goggins and Glen Matten, who’ve come up with a meal plan which involves drinking three sirtfood green juices per day, alongside sirtfood-rich meals. Tests at a swanky KX Gym in London’s Sloane Square where the plan was originally developed found that the average dieter lost seven pounds in seven days, without muscle loss.

The idea behind the diet is that certain foods activate sirtuins which mimic the effects of fasting and exercise and help regulate fat and glucose metabolism.

So what can you eat? As well as chocolate (as long as it’s at least 85% cocoa) and red wine (ideally Pinot Noir), other sirtfoods include miso soup, tofu, olives, kale, turmeric, blackcurrants and green tea. Caffeine addicts will be pleased to hear that coffee is also a high in sirtuins.

However the diet isn’t all wine and chocolate – during the first three days, calorie intake is limited to 1000 calories (three green juices and one meal, all rich in sirtfoods), followed by 1,500 calories on days four to seven. After this you move on to a 14-day maintenance phase, and the idea is that you continue to include sirtfoods in your daily diet. Typical Sirtdiet meals include prawn stirfry with buckwheat noodles and aromatic chicken breast with kale, red onions and a tomato and chilli salsa.

Sirtfood converts include model Jodie Kidd, boxers Anthony Ogogo and David Haye, Olympic champion sailor Sir Ben Ainslie and England rugby player James Haskell. And there is some science behind it. A 2012 study found that a sirtuin called Sirt6 lengthened the life of male mice by 15.8%, and another study found that Sirt1 could improve metabolism in mice fed a high-fat diet. However, its detractors argue that the weight loss simply comes from calorie restriction which cannot be sustained long term.

Frida Harju, in-house nutritionist for health app Lifesum said: ‘The Sirtdiet doesn’t focus on weight loss after the initial stages, but rather on how to change your life into a healthier lifestyle. Sirtuin works like most of the other antioxidants, it protects the cells from aging. If you take care to add sirtuins to your diet, they may help you stay healthy.’