We’re going to let you in on a little secret. Most popular healthy diets that are touted for weight loss—from Paleo to Mediterranean and vegetarian—share many of the same basic principles. All involve eating whole foods (as opposed to packaged and processed) and filling your plate with quality sources of protein, healthy fats, complex carbohydrates, and vitamin-, mineral-, and fiber-rich vegetables. (Again, we’re talking about the ones that fall somewhere on the healthy spectrum, not unhealthy fad diets like, ahem, the Grapefruit Diet. However, each proposes a slightly different path that leads to fulfilling those principles. In this column, we’ll be breaking them down for you one by one so you can figure out which (if any!) is right for you. We’ll quickly explain the facts and then provide quick, actionable tips on how to follow the diet as part of a Nutritious Life.
The trending Sirtfood Diet promises to help you lose seven pounds in seven days. It made headlines when singer Adele said it was the secret to her recent weight loss. But, is it safe — and more importantly sustainable? We have the Sirtfood Diet decoded.
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What is the Sirtfood Diet?
This diet’s foundation rests on research surrounding sirtuins (SIRTs), a family of proteins found in the body that may play a role in metabolism, inflammation, aging and chronic diseases. Certain polyphenols (plant compounds that act as antioxidants) may increase levels of sirtuins in the body. Diet founders, Aidan Goggins and Glen Matten — who refer to SIRTs as your body’s natural “skinny genes” — have named foods high in these polyphenols as “sirtfoods,” claiming they will activate mechanisms controlled by your body’s SIRTs to burn fat. By combining these sirtfoods with calorie restriction, the founders state your body will produce higher levels of sirtuins, which will then result in greater weight loss.
What You Eat
The first phase of the diet lasts one week. During the first three days, you’re restricted to 1,000 calories from one meal of sirtfoods and three green juices (recipes found in The Sirtfood Diet book). The rest of that first week you can consume two sirtfood meals and two green juices adding up to 1,500 calories per day.
In the second two-week phase, you can eat three sirtfood meals and one green juice a day.
After these phases, you’re encouraged to include sirtfoods in your diet and eat mostly plant-based meals in order to maintain results.
What You Don’t Eat
This is where it gets a little tricky. The Sirtfood Diet has a long list of what you can eat and focuses on having you consume those recommended sirtfoods. But while no food is technically off limits, the severe calorie restriction in the first phase of the diet means you won’t be able to eat many foods outside of the Sirtfood meals and juices. Goggins and Matten promote that by focusing on eating as many sirtfoods as possible, you won’t have much space left for other foods and beverages.
Pros and Cons
A pro of this program is that sirtfoods are nutrient dense foods that are high in health-promoting plant compounds — and they are great choices to incorporate into your meals regardless of the type of diet you may follow.
There are some studies suggesting the health and weight loss benefits of sirtuins —showing an increase of fat loss, reducing inflammation, and combating aging and age-related diseases — but overall, the research is still pretty slim.
One study found that mice genetically engineered to have high levels of the sirtuin SIRT1 were leaner and more metabolically active. In addition, researchers found that increased sirtuin activity in yeast extended their lifespan by 70 percent. While this research sounds promising, there is no evidence that this will have the same effects on humans — as well as no long-term studies to support sirtfoods being more effective than any other calorie-restricted diet.
Also, it’s important to note the Sirtfood Diet has the potential to cause some negative health effects. Extreme calorie restriction may lead to short-term weight loss, but it is difficult to sustain and can create nutrient deficiencies. You’re not only losing fat, but you’ll also lose important muscle mass needed to keep you fit and healthy. Severely cutting calories can even increase the stress hormone cortisol, which wreaks havoc on the body and can lead to weight gain.
The Bottom Line
Sirtfoods are healthy foods. But do they have the ability to turn on your “skinny genes,” as claimed by the diet founders? The science is shaky. Chances are this plan may “work” in the short term because of the calorie restriction. But, there’s no magic bullet here. Instead of following this very restrictive diet, incorporate these delicious sirtfoods into a healthy diet and lifestyle.
Keri Glassman, MS, RD, CDN, is a renowned celebrity nutritionist, healthy cooking expert, and wellness thought-leader. She is the founder and CEO of Nutritious Life and The Nutritious Life Studio, an online certification that provides unparalleled, forward-thinking education to individuals of various backgrounds looking to establish successful careers in the health and wellness industry.
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