Developed by two UK-based men with master’s degrees in nutritional medicine, the diet has become very popular among celebrities and athletes in the UK. Both Pippa Middleton and Adele are rumored to have followed this plan. Like many other diets, the Sirtfood Diet touts effective and sustained weight loss, incredible energy and glowing health. But is the Sirtfood Diet another diet fad, or is there any truth to its claims?
About the Diet
The plan claims that eating certain foods will activate your “skinny gene” pathway and have you losing seven pounds in seven days. Foods like kale, dark chocolate, and wine contain a natural chemical called polyphenols that mimic the effects of exercise and fasting. Strawberries, red onions, cinnamon, and turmeric are also powerful sirtfoods. These foods will trigger the sirtuin pathway to help trigger weight loss. The science sounds enticing, but in reality there’s little research to back up these claims. Plus, the promised rate of weight loss in the first week is rather quick and not in line with the National Institute of Health safe weight loss guidelines of one to two pounds per week.
The diet has two phases:
- Phase 1 last for seven days. For the first three days, you drink three sirtfood green juices and one meal rich in sirtfoods for a total of 1,000 calories. On days four through seven, you drink two green juices and two meals for a total of 1,500 calories.
- Phase 2 is a 14-day maintenance plan, although it is designed for your to lose weight steadily (not maintain your current weight). Each day consists of three balanced sirtfood meals and one green juice.
After these three weeks, you’re encouraged to continue eating a diet rich in sirtfoods and drinking a green juice daily. You can find several sirtfood cookbooks online and recipes on the sirtfood website. One green juice recipe found on the sirtfood website consists of a combo of kale and other leafy greens, parsley, celery, green apple, ginger, lemon juice and matcha. Buckwheat and lovage are also ingredients that are recommended for use in your green juice. They diet recommends that juices should be made in a juicer, not a blender, so it tastes better.
A day on the sirtfood diet might look like this:
Breakfast: Soy yogurt with mixed berries, chopped walnuts and dark chocolate
Lunch: A sirtfood salad made with kale, parsley, celery, apple, walnuts topped with olive oil mixed with lemon juice and ginger.
Dinner: Stir-fried prawns with kale and buckwheat noodles.
*Plus one sirtfood green juice per day.
You really need to plan and have access to the recommended ingredients in order to properly follow this diet. You’ll also need to invest in a decent juicer, which can cost you a minimum of $100. Besides the free recipes available on the website, you may need to invest in some of The Sirtfood Diet cookbooks.
Seasonality of ingredients makes it a bit tough to get strawberries and kale certain times of the year. It’s also tough to follow when traveling, at social events and feeding a family with young kids.
The diet itself cuts out numerous food groups and is limiting. Dairy foods, which provide an array of essential nutrients including several that most folks lack, aren’t recommended on the plan. Further, the polyphenol-rich food matcha often contains lead in the tea leaves which is potentially dangerous to your health especially when taken regularly. It also has a strong and bitter flavor, as does 85% dark chocolate, which is also recommended.
The Bottom Line: Polyphenol-rich foods can certainly be included in a weight loss plan, but they aren’t the basis for an entire diet. You most certainly don’t need wine and dark chocolate every day, plus too much matcha is potentially dangerous.
Toby Amidor, MS, RD, CDN, is a registered dietitian and consultant who specializes in food safety and culinary nutrition. She is the author of The Greek Yogurt Kitchen: More Than 130 Delicious, Healthy Recipes for Every Meal of the Day.
*This article was written and/or reviewed by an independent registered dietitian nutritionist.