Man tries 'world's healthiest' diet' for a week and is stunned by three changes

A fitness guru put himself to the test by attempting what he touted as the "world's healthiest diet" for a full week.

Will Tennyson was inspired by the dietary habits of people living in one of the Blue Zones around the world – Okinawa in Japan. Blue Zones refer to areas where people have been found to live longer than normal and were explored in Dan Buettner's Netflix documentary Live to 100: Secrets of the Blue Zones.

Drawing inspiration from Okinawa - known for its all-natural eating habits - Will laid out a simple guideline for his food shopping spree: "For this grocery haul I only have one rule, it needs to be one ingredient; it has to be foods that come naturally from the earth."

During his experiment solely with natural foods, Will experienced changes in his energy levels, digestive system, and skin. His journey through each day and the outcomes are detailed below.

When visiting Whole Foods, Will stocked up on steaks, salmon, chicken breasts, legumes, eggs, an assortment of fruits, vegetables, and nuts. While on the hunt for natural snacks, he pondered: "As I was looking for snacks, I started to wonder how often do I truly pay attention to what I'm eating? As society becomes growingly health conscious, food brands have become better at marketing their products as healthy eating."

Scrutinising the maze of options labelled as 'healthy' he remarked: "There are so many options that look good at first glance that I probably pick, only to find they are filled with additives. Literally nothing in this aisle that I can eat - I have been looking everywhere for a snack.

"It is actually insane and really eye opening to be honest."

On day one, his breakfast included three eggs, tomato slices, and half a Japanese sweet potato – an Okinawan staple. Weighing in at 198.2lbs, he was eager to monitor changes in his energy, mood, and skin throughout the week.

For lunch, he savoured "delicious" ground beef, cauliflower rice, and vegetables. Yet, as the day progressed, he faced his first hurdle: hunger.

With limited snack options, mainly fruit, he admitted to underestimating the challenge and felt overwhelmed. Dinner meanwhile featured steak, chipotle bowls, rice with black beans, and a mix of peppers, onions, and tomatoes.

On the second day, breakfast was a repeat of Japanese sweet potato, salmon, and three eggs. A gym visit revealed he couldn't have his usual supplements, leaving him to hydrate with water alone.

He shared with his audience that he was only eating until 80% full, noting: "I feel light, I feel less sluggish and I feel a lot more sharp, kind of like the feeling when you fast, and I think that's because you are not spending so much time digesting all of this unnecessary food so it feels really good."

To resolve his snacking issue, Will turned to the internet for ideas and whipped up a natural baked almond butter banana, which he likened to a protein bar and rated 9/10.

Speaking about how he felt, he said: "I don't know if it is too early to say but I actually feel great right now. From the moment I woke up to right now I have felt the same. I have had no energy dips, no brain fog, just feeling fantastic."

He noticed a decrease in his appetite, attributing it to the consumption of high-quality food rather than constant hunger.

For dinner, he dined on a combination of chicken breast, butternut squash, and avocado, which led him saying: "It is really starting to make me realise how many little things I add to all my meals that have a bunch of crap in it and it is concerning, it is kind of scary."

Day three saw Will experiencing a mixed bag of results. The definite plus was an improved digestive system, with frequent and "phenomenal" bathroom visits.

But sleep eluded him – he endured a pounding headache through the night, attributing it to withdrawing from certain items in his diet.

His breakfast featured an ample grapefruit, and despite cutting many things out, he was grateful coffee remained on the menu as it's natural; otherwise, he joked he'd be in quite a "state".

In pursuit of another natural treat, he whipped up a carrot cake but couldn't bring himself to finish it, finding it unappealing without the usual, more delicious ingredients.

On day four, Will described a sensation of being "extremely empty and light" which, though not necessarily unpleasant, was unfamiliar. Observing further improvements, he noted his skin appeared more even-toned. Post-gym, he positively mentioned the absence of headaches, concluding that he felt "really good".

Enjoying a creative snack, he indulged in chocolate avocado peanut butter pudding and rated it a perfect 10/10. Skipping the hassle of making dinner, he opted with his wife for an all-natural meal at Freshii, although it didn't quite hit the spot.

Here he experienced another headache but noted it was less severe. His spirits lifted, saying: "Today is the first day where my mood is pretty good. The first couple days I was kind of snappy, and agitated, things were irritating me that wouldn't normally, which is kind of concerning. But I have no gas, I have no bloating."

However, a glance in the mirror during his home workout led to concern: "I looked at my physique in the mirror and I was shocked to my core. Something is not right. I don't feel as sharp as I usually am for me, I feel a little bit softer."

He couldn't put his finger on the change but expressed not feeling like himself: "I just don't feel like my normal self - I don't feel as tight and ready to go, whatever that means."

Later needing a snack while out, he found the only natural option at a petrol station - a modest $5 fruit pot.

Will lamented the absence of his typical breakfast treats, missing sugar-free syrup, rice cakes, Greek yogurt, and carton egg whites.

He ditched the processed foods and was feeling the pinch, both physically and financially. Reflecting on his new diet, he shared: "I feel like I am actually forcing food down and that is just because I think the meals are way more substantial with nutrients and especially fats. I am not used to having a very high fat meal in the morning."

Will also noted the impact of his altered eating schedule, saying: "I really don't know if I can maintain this lifestyle. I am almost on the too intense side of the spectrum with the all natural stuff. I feel like the egg whites and greek yoghurts should be OK but I am just trying to take this extra seriously."

Despite the challenges, he acknowledged a positive shift in his perspective: "But I already know when this is done I am going to have to incorporate some stuff back in. However, it has certainly opened my eyes and made me want to reduce some of the crap I have been eating - because it is kind of scary."

His evening meal was a testament to his commitment, featuring homemade turkey burgers sans buns, accompanied by homemade guacamole, onion, mushrooms, and sweet potato fries.

As he wrapped up his week-long dietary experiment, he found himself taken aback by an unexpected revelation on the final day.

"I ended up losing roughly two and a half pounds this week which was kind of unexpected," he said. Will said that sustaining the diet was a challenge due to its restrictive nature, saying it was "incredibly limiting".

Yet, the experience ignited his determination to eliminate certain unhealthy foods from his diet as he remarked: "It is pretty crazy the lengths I typically go to to find these like diet hack foods and making these massive volume meals to keep me full only for it to keep me hungry all the time."

The diet overhaul led to positive changes; as Will commented: "The second I lowered the volume and focused on the better quality, not only was I fuller, but I also felt better, my energy was better, my gut felt good and I feel like my skin has a really good complexion now.

"So it has been an overall pretty good and eye opening experience. I think a lot of us forget that health is about feeling good inside and out and not only the out. So take care of yourself, be healthy, watch what you put in your body."

In summary, Will pinpointed three major health benefits post-diet adjustment: amplified energy, improved gut health, and enhanced skin quality.

As experts from Zoe, a leading science and nutrition firm, reinforce, there's a powerful link connecting diet and wellbeing—"looking after your gut health by eating gut-friendly foods can directly affect your energy levels".

Dr Will Bulsiewicz shed light on the importance of gut health by stating: "The most basic and most essential function of our gut is the digestion of our food. This includes the breakdown of ingested food, absorption of nutrients, and elimination of waste. When things are working properly, things are effortless and in rhythm."

However, when disruptions occur in digestive health, symptoms like fatigue quickly become apparent.

To bolster one's gut health, expert Zoe suggests a diet rich in probiotics, foods containing prebiotic fiber such as onions, garlic, and mushrooms, and promotes eating an impressive variety of 30 different plants each week while cutting down on ultra-processed foods.

Furthermore, they proposed healthy snack combos for that much-needed energy boost, including options like carrots with hummus, apples smeared with peanut butter, avocado slices atop wholegrain bread, and a classic mix of yoghurt with fruit.

To watch Will's YouTube video in full, you can do so here.