A US woman who attempted the drastic diet associated with Adele's major weight loss says that while she did indeed lose weight over a week, she was also left feeling dizzy, sick and lightheaded.
YouTuber Kayla Nelson documented her week attempting the super-strict Sirtfood diet, which along with an intense exercise regime has been credited with the 'Someone Like You' singer losing 50kg.
According to UK nutritionist Rob Hobson, 'Sirtfoods' are actually foods high in sirtuin activators. Hobson told Marie Claire this is a type of protein which can protect the cells in our bodies from becoming inflamed, with research also showing they can help regulate your metabolism, increase muscle and burn fat.
Popular Sirtfoods include apples, dark chocolate, red wine, blueberries, olive oil and buckwheat - but while that all sounds great (especially the wine), the first week of the Sirtfood diet is nowhere near as fun.
Dieters are told to limit their intake to 1000 calories a day for a week, which includes three green juices and one Sirtfood-rich meal.
In her video 'I tried Adele's weight loss diet' which has now been viewed over 1.2 million times, Nelson drives to several supermarkets to get the ingredients to cook the meals, and also attempts to adhere to Adele's intense exercise regimen which includes cardio circuits and reformer pilates.
But it wasn't long before Nelson was left "starving and lightheaded" and suffering from headaches after only drinking kale and apple juices, and restricting her calorie intake so drastically.
At one point during the video, Nelson suffers an intense migrane because she's "undernourished". When attempting Adele's reported pilates regime, Nelson said she had to "slow down and take a couple of breaks".
"At times I was getting a little bit lightheaded because, you know, I only had three juices today, so that was tough."
At the end of the gruelling week Nelson had lost 3kg, which she completely credits to "water weight".
"Not to be TMI, but the green juice and drinking all the water keeps you very regular," she said.
"It's really easy to lose weight that way when you're drinking lots of juice and it just goes right through you."
US dietician Sophie Medlin told Get the Gloss she wouldn't recommend the Sirtfood diet, as "keeping this up long term can prove very difficult and often requires big shifts."
"While we may encourage some of the healthy foods, strict regimes and replacing meals with juices often lead to difficulties with people's relationship with food and can lead us to lose sight of how much weight loss is too much."