The bulletproof diet

mens fitness
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Clint Warren is a personal trainer, motivational speaker, blogger, founder of Stacked Agency – and an ex-con who devised an ingenious way to stay strong and ripped in prison, as seen in the June 2014 issue of Men’s Fitness. He tried the Bulletproof Diet – a low-carb, natural food-based eating plan containing lots of fats – and here he explains why and reveals whether or not it was successful.

For years, I’ve tried all types of diets with mixed results. I’ve ‘gone Paleo’ (kinda), experimented with intermittent fasting (with good results), and done the traditional high-protein, low-fat bodybuilder-style diet. Before I discovered the idea of ‘going Bulletproof’, I was still eating what many believe is a healthy diet: one high in protein and low in fat and carbs. But I struggled with occasional bouts of binge eating and craving sweet foods, as well as poor sleep and energy dips in the afternoon.

I first read about the benefits of a high fat diet – how eating ‘good’ fats, such as the monounsaturated and polyunsaturated ones in fish, nuts and olive oil, can help your body burn fat, fuel performance and help you build muscle – while reading by David Perlmutter’s book Grain Brain, which recommends a low-carb, high-fat diet. A friend then mentioned the name Dave Asprey, creator of The Bulletproof Diet. I found similarities between Perlmutter’s and Asprey’s advice, and was impressed by the rigid scientific evidence both used to back their findings. I decided going Bulletproof was worth a try.

Check out Clint Warren's prison workout secrets, developed during his time inside. 

I started by buying Bulletproof Coffee, which gave me a nice jolt of energy and focus in the morning. This is a blend of high-quality coffee beans with medium-chain triglycerides (MCT) oil and grass-fed butter. It sounds strange, but it tastes fantastic. I got in touch with Asprey and he sent me a cheat sheet, which I began to follow. This suggested that my diet should consist primarily of organic vegetables, 50-70% of my calories should be coming from high-quality fats, and I should limit carbohydrates and avoid gluten, processed, inflammatory and genetically modified food. He gives more detail in his upcoming book, but that’s the gist.

Where I usually struggle when following these diets is preparing the meals, so I enlisted the help of Cross Cuisines, which delivered Paleo meals to my local CrossFit gym. In order to increase the fat content, I doused them in grass-fed butter. My new meal breakdown looked something like this:

Breakfast Bulletproof Coffee (made with Bulletproof coffee beans, 2tbsp MCT oil and 2tbsp grass-fed butter)

Lunch Protein shake (four raw eggs, two scoops of beef protein isolate, 4tbsp coconut oil and 2tbsp almond butter) or large salad loaded with avocado, topped with olive oil and grass-fed steak. I also added two to three scoops of Greens Plus in a separate shake to supplement vegetables.

Dinner Cross Cuisines meal, usually consisting of 170g lean protein, a serving of vegetables and a serving of carbohydrates (typically sweet potato). I added 3tbsp grass-fed butter and a large serving of steamed organic broccoli.

Supplements I took all of Asprey’s top 10 supplements

One concern I had was that by switching to a high-fat diet I would sacrifice athletic performance because I’d have less fuel for running. But after I followed this diet as strictly as possible for three months, without any changes to my training, I won a local CrossFit competition. The high-intensity, protracted nature of these events means you need lots of fuel to get through them so the Bulletproof Diet clearly had a benefit there. This chimes with the advice of leading sports physiologist Professor Tim Noakes, who says the body is designed to burn fat for fuel rather than carbohydrates – especially omega 3 fats, which you get from oily fish such as salmon and mackerel, nuts and seeds. 

On the strength side I set new personal best on all major lifts. I hit a 300lb [136kg] clean, 265lb [120kg] clean and jerk, and a bench press of 320lb [145kg]. My times on the CrossFit workouts dropped to PBs as well – I completed Elizabeth in 5min 38sec and Helen in 8min 50sec. I also dropped around 11lb [5kg] and my cravings for any type of junk food disappeared entirely for the first time in my life.

All this made it clear to me – fat provides fuel without making you pack on the kilos. And the benefits didn’t stop there: my general levels of energy and sleep improved too. I’ve struggled my whole life with sleep, having trouble falling asleep and then waking up multiple times at night, and I’ve tried everything from yoga to exercise to meditation. On Bulletproof I started falling asleep faster and sleeping through the night.

Of all the diets and workouts I’ve tried, this is definitely the one that has shown the most tangible benefits. If you’re looking for something to get your fitness back on track in 2015, I highly recommend it.

Visit Clint Warren’s blog or Stacked Agency

Bulletproof coffee explained


A drink that combines coffee, butter and oil to encourage your body to burn fat for energy. Bulletproof, the brand, was created by entrepreneur and ‘biohacker’ Dave Asprey.


Asprey got his inspiration after feeling the rejuvenating effects of yak butter tea in Tibet. His version combines the metabolism-boosting effects of caffeine with healthy fats to keep you feeling full and energised until lunchtime.


Naturally, Asprey recommends using his official Upgraded brand of coffee beans and MCT (medium-chain triglycerides) oil. You can make your own version by adding 2tbsp unsalted, grass-fed butter and 2tbsp coconut oil (which contains MCTs) to black coffee, and blending it together.   


MCTs, like caffeine, have been shown to improve cognitive function, and coconut oil also contains lauric acid, which has antibacterial properties. Grass-fed butter is rich in nutrients including vitamin K, which is crucial for bone and heart health. When you haven’t got time for breakfast, a buttered coffee is a decent alternative.