I tried Adele's "miracle" Sirtfood diet for a week and this is what happened
Kale me now
I would like to preface this article by stating that crash diets don't work. If you're thinking of going on a diet for weight-loss reasons, please consult a doctor, a licensed dietician, or a nutritionist beforehand.
If you would kindly join me in a flashback to May 2020, you may remember a certain birthday post from the inimitable face of pop music, Adele. In the photo, the singer is pictured grinning behind a wreath of white and blush roses, wearing a black, puff-sleeved minidress and a brand new head of highlights.
In addition, as most of the comments kindly point out, the singer debuts a much slimmer frame after her five-month social media hiatus. While the world's focus on the singer's weight loss was rife with problematic and fat-phobic implications, there is no doubt that the "secret" to her transformation was the subject of speculation for months after.
Well, speculation soon turned to investigation, and that unearthed the answer: The Sirtfood diet. Well, that, in addition to access to a personal trainer and a personal chef, of course. Following the big reveal, the Sirtfood diet has swept the globe, making fantastical promises of rapid weight loss, improved health, and the complete "reprogramming" of the body. Yeah, it does sound too good to be true, doesn't it?
What is the Sirtfood diet?
Welcome to the world of Sirtfoods—the overwhelmingly green, upsettingly kale-filled, and questionably "healthy" fad diet that has taken the world by storm. Created by Aidan Goggins and Glen Matten, two nutritionists who vehemently insist that their diet is not a fad, the Sirtfood diet is a 28-day plan with two phases. Phase I combines "moderate" caloric restriction with the "top 20 Sirtfoods" to help dieters "lose 7Ibs in 7 days with increases in lean muscle". The details and the diet plan can be found in Goggins and Matten's book, The Sirtfood Diet: The Revolutionary Plan for Health & Weight Loss, but here is a excerpt from page 17 for your convenience:
"During the first three days, your calorie intake will be restricted to a maximum of 1,000 calories per day. This will consist of three Sirtfood-rich green juices, plus one full meal rich in Sirtfoods per day. For days four to seven, your calorie intake will increase to a maximum of 1,500 calories. Each day will comprise two Sirtfood-rich green juices and two Sirtfood-rich meals. By the end, you can expect to have lost an average of 7Ib (3.2kg)."
Phase II is the 14-day "maintenance" phase—caloric restriction is halted, and the point is to lose weight steadily by "eating a wealth of Sirtfoods and drinking one maintenance Sirtfood juice".
Here are the foods in question:
In addition to rapid weight loss, the Sirtfood diet also promises to ramp up your metabolism, increase the efficiency of your muscles, reduce inflammation, and repair damage in your cells. Let's just get into my thoughts on this, shall we?
Debunking the Sirtfood diet
I read this book from cover to cover. So, let's unpack the science behind sirtuins (for context, I did do a degree in Biomedical Science, with a focus in endocrinology):
According to Goggins and Matten, Sirtfoods are a group of polyphenol-rich foods that "switch on your body's fat-burning powers". These polyphenols, which includes reservatrol (found in red wine) and quercetin (found in red onion, kale, and rockets), supposedly activate the body's "skinny" sirtuin gene, which leads to the production of seven proteins known as SIRTs, or silent information regulators.
One thing that is especially frustrating about this is that it's not entirely wrong. The SIRT family, particularly SIRT1, has been linked to many biological processes. This includes the increase of mitochondrial activity, the regulation of glucose and lipid metabolism, and the differentiation of adipocytes. In fact, a 2016 study in the International Journal of Molecular Sciences found that sirtuins may potentially help in the treatment of obesity. That said, most research comes from animals or in vitro experiments and has not yet been proven in human experiments.
In short, while the pair proudly conflates the research behind SIRT1 with their diet, it's all science-washing and cherry-picking facts to suit an agenda. The idea that Sirtfoods are responsible for "switching on your skinny gene" is not backed up by robust research. Further, while there is a lot of anecdotal evidence quoted in the book, there are only vague mentions of "clinical trials".
Were said trials double-blinded and randomised? Were control groups given standard calorie restriction without these "Sirt activators"? Was there a control group at all? There really is nothing to suggest that Sirtfoods are a more effective weight loss diet than any other calorie-controlled diet.
The reality of the situation is that your body is far more complex than "I eat this and this will certainly happen". However, don't just take it from me—following my concerns about the diet, I consulted nutritionist Delphine Lim to glean her take. I presented her with the Sirtfood diet's main claims, and here are some of her thoughts:
“[Phase I of the Sirtfood diet] is what we like to call the hyper-success phase, where you will take a huge step towards achieving the slimmer and leaner body you want with our clinically proven method for losing 7Ib (3.2kg) in 7 days. This will be achieved by powerfully combining moderate fasting (caloric restriction) with a specially designed diet very rich in Sirtfoods." — p78, The Sirtfood Diet: The Revolutionary Plan for Health & Weight Loss
"Firstly, the 1000kcal from day one to three of the diet is not 'moderate' calorie restriction. For context, in Malaysia, these are the energy requirements for a moderately active (PAL 1.6) adult: Women should be consuming 1840kcal a day, while men should be consuming around 2240kcal a day.
"Secondly, while the energy intake increases from day four to seven to 1500kcal/day, this is still below the recommended energy requirements for men and women. It might be okay for women to have 1500kcal/day, but it really depends on their height, weight, and physical activity levels. I can’t generalise for all, and neither can this diet.
"Also, the safe rate of weight loss per week is between 0.5-1kg. Losing weight faster than this can increase the risk of health problems such as gallstones and malnutrition)—an exception would be if it is done under medical supervision. Sirtfoods might activate sirtuins, but you're more likely to be losing weight because you’re essentially having a calorie deficit."
“One of the findings of our pilot trial was that the muscle mass of the participants didn't drop; in fact, it often increased." — p38, The Sirtfood Diet: The Revolutionary Plan for Health & Weight Loss
"It is possible that muscle is retained for Sirtfood diet participants because they were on the diet for only a week and were using up fat stores. I would definitely not recommend it for the long term—your metabolism may slow down when you’re not eating enough calories for your body to maintain basic bodily functions and start to tap into protein (muscle) stores."
"At the end of the day, any “diets” out there that are restrictive and promises that you will lose more than 1kg a week is not something I would recommend. I do have nothing against Sirtfoods, though I think there needs to be more promising research before you can conclude that they are great for weight loss (AKA it needs more human clinical trials)."
With all of this in mind, I wanted to give the diet a try. After all, despite its focus on weight loss, the Sirtfood diet does also claim to be suitable (and even beneficial!) for people of normal weight. Granted, my BMI is 19.8, so I while definitely fall into the "normal" category, Goggins and Matten suggest that I heed caution as my BMI may fall below 18.5—something I definitely kept in mind throughout the week. I was just curious about what this diet would do to my body. Would I gain muscle mass? Would my skin clear up and smooth over? Would my body be "programmed" to be super ripped forever? Find out now in my Sirtfood journey ahead!
NOTE: If your BMI is low, you should probably give the diet a miss.
My experience with Phase I of the Sirtfood diet
The book has pre-planned meal ideas to choose from (there are both meaty and vegetarian options, FYI), so I worked from there. Here is my experience with the diet.
I started the morning off with a weigh-in: 54.0kg. I also measured my waist, which clocked in at 66.5cm. Then, after chugging my usual morning litre of water, I decided to give the Sirt juice a try. Now, I was pretty excited to try the Sirt juice—in theory, I actually find the blend of matcha, kale, rocket, parsley, celery, green apple, and lemon quite appealing. I like all of those things separately, so they must be better together, right? No. In practice, it tastes like a belt. A "green" belt, but a belt nonetheless.
I kept drinking it, thinking that it was going to grow on me, but it only got worse with every sip. Here is what I still don't understand: What extra benefits do I reap from drinking the juice in lieu of just eating the fruits and veggies whole? After all, the whole juicing trend has been debunked countless times. Either way, while I love juice on a regular day, I don't love it as a meal replacement.
That aside, I managed to last until around 5pm without feeling particularly hungry, partially due to my being used to Ramadan and also because I'd spent the whole weekend bingeing on sweet and decadent treats. Really, at this point, this diet was looking to be a nice break from indulgence. With that said, I did begin feeling a little faint around the 6pm mark, but I couldn't decide whether that was due to a general lack of sleep over the last week, or whether it was food-induced. Regardless, I opted to have my dinner a little earlier than my usual 8pm.
In short, I wasn't pleased with the meal. After a day of not eating, the portion was genuinely comical. Needless to say, I ate every last morsel while the diet's promise of "satiety and fullness" post-meal echoed in my groggy head. Spoiler alert: I did not feel full. Not even a little bit.
I went to bed feeling quite nauseous, at which point I decided to eat my optional snack. Did it help? You guessed it—20g of dark chocolate did not do anything to curb the hunger pangs. Feeling a little peeved, I then headed back to sleep for what would be an absolutely sleepless night. Why? I was absolutely freezing. Yes, despite having a huge duvet to cover me and no air conditioning unit turned on, I couldn't get to bed because I couldn't stop shivering.
Again, I started the morning off with a weigh and a measure: 55.2kg and a waist measurement of 65.5cm. If you're paying attention, you might have noticed that my weight actually increased on day two. This is pretty normal for me—I tend to fluctuate between 53~56kg from water weight and bloating, so I didn't think too much of it.
What I was thinking about was how hungry I was. I was also acutely aware of how faint I felt. In fact, my energy levels suffered a distinct drop on day two; something I'm not surprised by, given how little I'd eaten in the last two days. I tried to remedy the faintness with one of the juices to no avail, so after consulting Lim, I broke the diet with a singular banana.
This seemed to help a bit, and I was able to get on with my day, though I was definitely more unmotivated (and hangrier) than usual. One good thing I discovered from day two? Adding extra lemon makes the juice so much better. One less good thing I learnt? This diet is not compatible with my guts. I won't disclose the details.
Come 6pm, I was ready to eat and I was pleased to find that this meal was much more filling than the last. Unfortunately, satiety did not last more than an hour, and I found myself terribly tempted by a slice of apple strudel after dinner. Oops.
On day three, my weight clocked in at 52.5kg and my waist measured in at 65.3cm. To start my day, I found myself with a killer headache and a case of the shakes (something I usually get when I'm faint and hungry). Luckily, it was easily mitigated with a slice of egg bread (better known as French toast). I know, I know—I broke again. However, in my defence, I was still very hungry after my small cheat meal, so I feel like it was justified.
I can't say the same for the rest of my cheeky cheats, though. Day three had me at breaking point, and it did not help that my family was basically dangling all of my favourite treats right in front of my face. In total, I had exactly one mouthful of salt and pepper crisps, a singular (modest) bite of a brownie, and a literal sip of soursop juice. Oops.
All was not lost, however—because I'd treated myself so much, I skipped out on my designated portion of dark chocolate. Goody me!
Welcome to day four. Today was a special day: Not because I had weighed in at 51.9kg nor because my waist measured in at 64.5cm, but because I was now entitled to two whole meals today! I was super eager to chomp down on breakfast—this morning's menu called for the Sirt omelette. I have to say that while it didn't look amazing, it was actually really good. In fact, I will concede that some of the Sirtfood diet meals are genuinely quite tasty. That said, at this point, I'm really getting tired of kale and green beans. Further, despite the increase in food portions, I did find that I was still hungry post-meals. Even so, at least the pangs were nowhere near as severe.
I do have to say that by day four I was finally used to the juice. Don't get me wrong—I still don't like it, but I also wasn't gagging with every sip. That was a nice change. Just to reiterate: If you're still keen on trying the diet, remember that lemon is your best friend when it comes to the Sirt juice. While it doesn't completely mask the belt-ness, per se, it does add a good helping of tartness that significantly offsets it.
Day 5 was pretty rough. I weighed in at 52.1kg and my waist measured in at 65.7cm (post-lunch—I forgot to do my morning measure). I started the day feeling especially groggy and grumpy from an all-nighter I had pulled. On the bright side, because I was up so early, it meant that I was actually awake at breakfast time for once.
I was, of course, still hungry post-breakfast, but I had decided against having a snack. I figured that after staying up all night, I was probably due for a long, long nap. So, if anything happened between the hours of 12pm and 5pm that day, I wouldn't know; I was fully passed out and in the bliss of slumber.
Here is the complication: Come dinnertime, I was still groggy from my nap, and I had actually forgotten about the diet entirely. Cue me indulging in a little hotpot, only remembering that I'm supposed to be having Sirtfood when it is too late. Oops. At least there were vegetables in the hotpot (though, admittedly, none of them were particularly "polyphenol-rich"). My bad, though I can't say I have any real regrets.
Another day, another measurement: Day six saw me weighing in at 52.2kg and measuring 66cm at the waist. At this point, I was done with the diet. Despite having two meals a day, I was still extremely lethargic, my cravings were out of control, and I could feel a binge coming on soon.
The straw that broke the camel's back (read: my back) was the soba noodle miso soup. As someone who regularly makes miso soup as a comfort meal, I cannot express how much I despise the idea of kale and celery coming anywhere near the dish. Fun fact: It's even worse in practice. While many of the recipes in the Sirtfood diet actually sound really tasty, this was a genuine affront to my senses. I would describe it as genuinely upsetting. In my subsequent anger following dinner, I managed to consume a handful of crisps, a small lamb chop, and a thin slice of shabu-shabu beef. No regrets there.
Day 7 / My results
Finally, it's day seven! My final weigh-in for the week clocked in at 52.4kg, and my final waist measurement was 64cm. That is a 1.6kg weight loss and a 2.5cm reduction in waist size. So, did I notice any positive transformative changes in me this week?
Aside from the crabbiness, I can't say that I did. On my frame, which is already on the thinner side, the physical differences in my 1.6kg weight loss and waist reduction weren't very apparent. I did not look more toned nor feel stronger in any way. I did, however, look exactly how I felt—pale, drained, and weak.
I also didn't notice any marked changes in my skin, bar a little less dryness than usual (no doubt thanks to the sheer volume of water I was drinking to curb my hunger). I admit that I was hoping to at least see an improvement in my acne or a veggie-induced glow, but I saw none. Further, the toll that the diet took on my digestive tract completely negated any positive effects I may have noticed anyway.
Obviously, you could argue that the cheats I had throughout the week may have tampered with my results. However, if you go by the logic of the book, the increased proportion of Sirtfoods in my diet should have theoretically delivered the proposed benefits regardless. No such observations here, though.
After experiencing the diet, I personally would not recommend it to anyone. While the food is surprisingly good (there are tonnes of recipes in the back that I definitely will keep trying), I feel that the restrictive nature of Phase I is far more intense than what is necessary. I also feel that it is counterintuitive to any goals of weight loss as it leaves dieters susceptible to bingeing. Further, I really have an issue with this diet claiming to not be a "fad diet". What it actually it is all of the fad diets that have ever existed, rolled into one terrible week. Pass.
Granted, this is a short-term diet, and you're supposed to repeat the cycle as and when you feel you need it. But, in my opinion, you're better off just eating a balanced diet. Heck, if you really wanted to, you would probably benefit more from jumping straight into Phase II with regular, moderate exercise—at least being given a wider range of food at regular intervals would be better for suppressing cravings and supplying the necessary energy for a workout in the first place.
As Lim so aptly puts it, "there are no shortcuts or magic pills to be healthier. A healthy, balanced diet and regular exercise are key. Overall, there’s no harm in having Sirtfoods in your diet, but please do not limit your diet to just Sirtfoods. Have a variety of plant-based foods—they contain phytonutrients that are great for you!"
PS: If you are going to try the diet anyway, feel free to eat as and when you feel faint—take care of your body and listen to what it needs. And please talk to a professional before jumping into the diet.
The opinion expressed above belongs to the writer and doesn't necessarily represent the views of BURO Malaysia.
For more diet stories like this, click here.