The Sirtfood diet has been in the news again this week after singer Adele showed off her slimmed-down figure on US comedy show Saturday Night Live.
Adele has previously credited her significant weight loss to the Sirtfood diet. Following her appearance on SNL, there was a spike in people searching the diet on Google.
But what exactly is the Sirtfood diet, and does it work?
What’s the premise?
Two nutritionists in the United Kingdom launched the Sirtfood diet in 2016.
The premise is that a group of proteins called sirtuins, which are involved in regulation of metabolism, inflammation and ageing, can be accelerated by eating specific foods rich in a class of phytonutrients called polyphenols.
Phytonutrients are chemical compounds plants produce to help them grow well or defend themselves. Research is continuing to shed light on their potential benefits for human health.
The idea is that eating foods rich in polyphenols, referred to as “Sirtfoods”, will increase the body’s ability to burn fat, boosting metabolism and leading to dramatic weight loss.
Common Sirtfoods include, apples, soybean, kale, blueberries, strawberries, dark chocolate (85% cocoa), red wine, matcha green tea, onions and olive oil. The Sirtfood diet gets some of its fame because red wine and chocolate are on the list.
Sirt science
Most research has looked at the sirtuin-mediated effects of energy restriction in worms, mice or specific body tissues. No studies have tested the effect of diets that vary polyphenol content on the action of sirtuins in mediating weight loss.
A search on PubMed, the scientific database of research studies, didn’t locate any human trials of the Sirtfood diet. So the short answer about whether the Sirtfood diet works or not is we don’t know.
The authors’ claims about effectiveness are based on anecdotal information from their own research and from personal testimonials, such as the one from Adele.
The best diet for weight loss is one that meets your nutrient requirements, promotes health and well-being, and that you can stick with long-term.