One way of ensuring the popularity of a trendy diet is for a celebrity to try it out and experience visible weight loss. The story of Adele’s weight transformation made international headlines in 2016, and the dietary plan she allegedly used, the sirtfood diet, followed close in her wake. The creators of this diet claim people will experience significant weight loss over a six-month period. Nutritionists say it may not be the best diet for some people, though others will likely experience weight loss.

The Creators of the Sirtfood Diet

In their 2016 book, Aidan Goggins and Glen Matten discuss their focus on “activating the skinny gene” through sirtfoods. According to Goggins’ website, he holds a master’s degree in nutritional medicine from the University of Surrey in the UK. He is a proponent of a holistic approach to medicine and nutrition. Matten graduated with the same degree and also trained at the Institute for Optimum Nutrition in the UK. According to Matten’s website, he also worked as a research nutritionist. The two teamed up for a previous book, The Health Delusion, published in 2012.

Sirtfood Diet Basics

The sirtfood diet focuses on eating foods that activate a class of enzymes called sirtuins. Animal studies suggest these enzymes improve longevity. Matten and Goggins claim that polyphenol-rich foods protect cells and reverse aging, with a long list of additional benefits. They also say that these foods jumpstart genetic pathways that usually require exercise and fasting to activate. Some of the foods the authors recommend are green tea, dark chocolate, citrus fruits, kale, and red wine.

The Two Phases of the Sirt Diet

The sirtfood diet consists of two phases. Phase 1 lasts for seven days. The guidelines call for a total of 1000 calories per day during the first three days. On these days, adherents eat three sirtfood green juices and one sirtfood-rich meal. On day four, the caloric intake increases to 1500 calories per day. Dieters add one meal and decrease their green juices to two. Phase 2 is a 14-day maintenance phase with three sirtfood-rich meals and one green juice each day.

After the Second Phase

Goggins and Matten state that the sirtfood plan is not a short-term diet but an ongoing way to incorporate sirtfoods into any daily eating plan. They say dieters can repeat phases 1 and 2 as necessary to maintain weight loss and to boost health. Additionally, the authors note that continuing a diet rich in sirtfoods improves memory, controls blood sugar, and repairs the damage resulting from free radical molecules that lead to diseases, including cancer.

Why Polyphenol-Rich Foods?

Polyphenols are compounds in plants that contribute the color to some flowers, fruits, and vegetables. Research shows that polyphenol-rich foods may decrease the risk of chronic diseases. The anti-oxidant and chemo-preventative properties offer protective benefits against cardiovascular and neurodegenerative diseases and certain cancers. Research indicates polyphenols exist in foods experts often recommend for a healthy diet. In addition to fruits and vegetables, olive oil, nuts, and whole grains are excellent sources.

The Facts About Sirtuins

Scientists discovered the primary functions of sirtuins in the 1990s. They found that the proteins play a crucial role in maintaining cellular homeostasis or balance. Seven sirtuin proteins work together to maintain cellular health. To function properly, these proteins require nicotinamide adenine dinucleotide or NAD+, which decreases with age. As NAD+ levels drop, sirtuin functions become limited. As a result of these findings, there has been a great deal of research into sirtuin and age-related disease. However, there is some controversy within the scientific community regarding the findings.

Requirements for the Sirtfood Diet

Specific details of the diet are available only in the book. Although there is a website with links to lists of plant-based foods called sirtuin activators, there are no recipes. Many other websites and cookbooks provide recipes that follow the diet guidelines. Because a large part of the diet focuses on juicing, a juicer is necessary. The sirtfood diet also relies on three key ingredients:

• Matcha, a finely ground powder made from green tea leaves, to prepare the signature green juice.
• Buckwheat, a whole grain that has high levels of resistant starch, to provide prebiotic effects that stimulate helpful bacteria.
• Lovage, an herb that tastes similar to celery, which some research suggests has antibacterial effects and can help reduce inflammation.

Benefits of Juicing

The sirtfood diet guidelines assert that juicing as an essential part of the plan. According to juicing proponents, drinking vegetables and fruit juices makes it easier for the body to absorb nutrients. However, there is no scientific research to support any assertion that juicing is a better alternative to eating fruits and vegetables. Juicing removes fiber, which not only contributes to fullness, but it also lowers cholesterol levels, helps control blood sugar, and reduces the risk of heart disease.

Safety of the Sirtfood Diet

The diet’s creators maintain that people who follow the guidelines will lose seven pounds in the first week. They also claim that the diet will improve memory and control blood sugar. However, the majority of the sirtuin research has been conducted on mice, yeast, and human stem cells, so there is little research to adequately determine the effectiveness of the diet. Some nutritionists worry about the severe calorie restriction of the diet, which is about 40 to 50% of the amount research suggests people need. This drastic deficit leads to loss of glycogen and water rather than fat. Sirtuins could be beneficial for people with diabetes, but more research is necessary to determine the effects of the diet’s calorie restrictions.

Critics of the Sirtfood Diet

Because the diet relies on sirtfoods, its purported benefits stem from research on non-human subjects. Some people criticize the validity of the weight-loss claims. The medical community warns against fad diets, which tend to promise quick fixes with few long-term benefits. Instead, most dieticians recommend eating a variety of foods in moderate servings and exercising regularly to maintain weight.