Fast This Way

by Dave Asprey

  On an intuitive level, it’s easy to know that certain foods make us feel good and others make us feel bad. Two millennia ago, the ancient Greeks interpreted these feelings in a spiritual way: they believed that eating and drinking allowed demonic spirits into the body and embraced fasting as a way to achieve purification by keeping the demons at bay. As naive as that might sound in the modern age, they were onto something. When we eat and drink, harmful agents do enter the body. Today we call them toxins. If they trigger inflammation, they are referred to as inflammogens.

  Chronic inflammation locks your body in a perpetual state of molecular stress as it struggles mightily to heal injuries that cannot be healed. Things go downhill from there as the inflammation response feeds on itself. Your intestinal lining becomes irritated, allowing bacteria and bits of undigested food to enter the bloodstream. The immune system correctly perceives these intruders as a problem and instigates even more of an inflammatory response. Toxins in the gut provoke the release of cell-signaling proteins known as cytokines, which are able to enter the brain and cause inflammation there as well. Adding insult to injury, a low-quality diet disrupts the Krebs cycle, the essential chain of chemical reactions that generates energy from the carbohydrates, fats, and proteins in your cells. Toxic substances interfere with the Krebs cycle, allowing electrons to leak away. Your body loses precious energy; the stray electrons, meanwhile, give rise to irritating, electrically charged molecules known as free radicals, which are another significant trigger of inflammation.

  As bad as that all sounds, the medical reality of it is even worse. During chronic inflammation, the immune system floods the surrounding tissue with specialized types of white blood cells—lymphocytes, monocytes, and macrophages—to clean up the accumulating damage. Over time, these cells often end up attacking healthy tissue and organs, leading to autoimmune disease. Inflammation has been identified in an underlying factor in cancer, rheumatoid arthritis, heart disease, diabetes, Alzheimer’s, and asthma. It contributes to obesity, fatty liver, and chronic kidney disease. Chronic inflammation turns your thinking foggy, and it accelerates the aging process.

  But you’d never consume anything that would do those terrible things to you, right? Bad news: you probably do it all the time.

  Supermarkets and convenience stores (and many restaurants as well) are crammed with foods made using low-quality, inflammation-stoking fats, such as those in corn and canola oil. Why? Because they are cheap. Big Food inexorably delivers the most easily marketable products—ones that are inexpensive, tasty, and pretty. Over the years, the industry systematically phased out expensive, high-value fats such as grass-fed butter, coconut oil, ghee, and even lard from healthy animals (lard was a part of the human diet for ages, yet until recently heart disease was rare). Your long-term health is not a part of the business plan. It takes about two years for the fats you eat to be incorporated into half of the cell membranes in your body. By then you’re not going to have any idea why you don’t have the energy and mental clarity you used to. Big Food won’t have any idea, either.

  Steering clear of all the processed foods made with those oils is really tough. Start reading some ingredient labels, and you’ll see what I mean. And that’s still only part of the inflammation challenge you face. You might decide that you’re going to eat healthy by avoiding or minimizing obviously toxic foods such as high-fructose corn syrup, sugar, and trans fats, all of which cause inflammation. But keeping the chemical demons at bay is not that simple. Plant-based foods such as bread, and even some vegetables such as bell peppers and kale, can cause inflammation, too.

  Inflammatory Foods That Cause Cravings and Make Fasting Harder

  * * *

  High-oxalate foods (which can induce your body to produce calcium crystals that are hard to eliminate): sesame, soy, raw kale, spinach, chard, beets

  High-histamine foods (containing a neurotransmitter that can cause allergies and cravings): fish sauce, soy sauce, leftover fish, leftover pork

  Phytic acid (which inhibits protein digestion): beans, grains, wheat, legumes

  Burned or charred meat, grains, or vegetables: high-temperature cooking creates toxic compounds, including AGE (advanced glycation end products), HCA (heterocyclic amines), and PAH (polycyclic aromatic hydrocarbons, found in soot)2

  High-lectin foods allowed (not recommended but sometimes allowed) on the Bulletproof Diet: tomatoes, potatoes, bell peppers, hot peppers, eggplant, beans, chickpeas

  Contrary to a common assumption, most inflammatory by-products are made by plants or microbes, not animals, for reasons that are rooted deep in the nature of evolution. If you are an animal and you don’t want to be eaten, you can generally run and hide. If you are a plant, you need to defend yourself in place: you can grow a hard, protective shell, like a walnut; you can sprout spines, like a cactus; or you can fill yourself with poison. The poison strategy is a really common one. Think for a second what would happen if you were to go into your backyard or your local park, pick the first leaf you saw, and eat it. Seriously, don’t do it! You’d very likely end up doubled over in pain.

  The plant world is full of inflammatory toxins that can find their way into your food. That’s true even of crop plants such as tomatoes or pumpkins, and it doesn’t take much of those plants’ leaves to mess you up. Back when my daughter was two years old, she ate two leaves from a pumpkin plant in our yard. She then spent the rest of the day farting and crying from cramps. Her body was reacting to proteins called lectins, which are present in many plant leaves to keep insects and predators and herbivores away. Lectin is sometimes called an antinutrient because of its harsh, inflammation-triggering effects.

  The plants that contain the most toxins are the least desirable and hence the cheapest—which means they are right at the top of Big Food’s shopping list. As long as it’s possible to make those plants taste good and delay the bad effects so that they don’t have any immediately obvious negative effects on your health, they will find their way into junk food. These days, you will find even low-quality plants being marketed as health foods. Take hummus as an example. It is full of lectins (chickpeas), but it’s a cheap source of calories compared to guacamole, so you find it everywhere, even though everyone knows that guacamole is healthier (and tastes better).

  A lot of people willingly—eagerly!—unleash other sources of inflammation into their bodies all of the time. You’ve almost certainly exposed yourself to this widespread food toxin: alcohol. Think about how you felt during a hangover. Was it painful? Were you immobilized? You can look at a hangover as inflammation in response to a common inflammatory microbial toxin from yeast. Even if you limit your drinking and build your diet around foods that don’t contain inflammatory products, you may still be causing your body damage through undisciplined eating habits. Your body can become inflamed simply if you eat at the wrong time or eat too much. Both the size of your meals and their timing are very important in determining the impact of the food you eat.

  This all sounds rather daunting, I realize. How can you possibly succeed when you have all of this biology and evolution and industry working against you? It’s true, inflammation will kick your ass if you let it. But you have a secret weapon, one that gives you a break from toxins and inflammation across the board. Fasting kicks inflammation’s ass, giving the digestive organs a chance to rest and reset while nothing inflammatory comes in, in the same way that we allow our muscles to recover after a hard workout.

  When you fast, your body takes energy that would normally be used to digest food and redirects it to healing and repair. Your cells need nourishment and oxygen to thrive, but lifestyle choices such as being sedentary or dietary choices such as overeating or eating toxin-laden foods that result in digestive issues promote cellular degeneration and what biologists delicately call apoptosis. Let’s just call it what it is: cell death.

  A low-quality diet and inactive lifestyle will slowly kill your cells—and you. Fasting gives new life to your body. When you
start fasting, one of the primary reasons that you feel better is that you’ve stopped consuming antinutrients. You’ve stopped eating bad oils. You’ve stopped eating the inflammogens that Big Food puts in there.

  You’ll start to wonder why you have so much more energy and mental clarity. Is it because of the ketones that turned down inflammation? Yes. Was it because when you stopped eating crap, it turned down inflammation? Yes. Was the power of those two together doubly powerful? Yes. Could you achieve this result even by eating a high-fat diet without any toxins in it? Yes again! I’ve been doing this type of diet for more than ten years, and I’ve taught hundreds of thousands of people how to do it successfully.

  Fasting can be flexible. Avoiding inflammatory foods can be easy and enjoyable. The key is learning which foods to cut out of your diet—the ones that I call kryptonite. Whether Mother Nature made it or a chemistry lab made it, you’ve got to avoid kryptonite. I’m here to help you do that. You can find a more detailed list—the Bulletproof Fasting Roadmap—for free online at daveasprey.com/fastingroadmap.3 I recommend printing it out and putting it on your fridge. In the meantime, here’s the short list of kryptonite foods:

  Soy milk, fruit juice, diet drinks, soda, sports drinks

  Corn, soy, beets, chard, collards, kale, spinach, eggplant, peppers, tomatoes

  Margarine, GMO oils, industrial lard, vegetable oil, seed oil, canola oil, peanut oil, cottonseed oil, sunflower oil, safflower oil

  Powdered milk, evaporated milk, soy protein, wheat protein

  Packaged salad dressings and sauces, caseinate, hydrolyzed gluten, MSG, hydrolyzed yeast

  To be clear, you can eat all these things and still benefit from fasting. It’s just a lot harder because you’ll be hungry all the time. Once you are liberated from kryptonite, you can become superhuman. During the biochemical cleansing process, your intestines, vital organs, and even your bloodstream will be purified. Diseased cells will be replaced by healthy tissue. This doesn’t just make you feel better, it might actually make you look better. All that new, healthy tissue can give you a more youthful appearance.

  DAVID AND HIS FOOD GOLIATH

  At this point, I’d like to share a little bit more about my journey to wellness, because a lot of it involved my own battle with inflammation and a wonky metabolism. Frankly, when I started out, my health was a shit show (that’s the scientific term for it). But if I could fix my body, you can, too. In fact, your path is probably going to be a lot easier than mine.

  When I was five years old, my family moved from California to New Mexico. We had no idea that the walls inside our new home were filled with toxic mold or that the abandoned gold and silver mines in the nearby desert where I liked to shoot guns (this was back before video games) were loaded with heavy-metal toxins, including lead and mercury. All I knew was that things were starting to go wrong with me. By the time I was fourteen, my body was breaking down so badly that I had chronic arthritis in both knees, persistent nosebleeds, and recurring bouts of strep throat. By my early twenties I was obese, squeezing into an XXL T-shirt, and even a triple pleat on my pants couldn’t hide the fat. I tried a bunch of diets. I worked out for ninety minutes every day for eighteen months straight, but I still couldn’t lose weight. The symptoms that scared me most were crippling fatigue and brain fog—I was always exhausted and had a hard time focusing on my career.

  In my late twenties, my doctor ran lab tests and told me that I was prediabetic and at high risk for a stroke and heart attack. In addition, I had hypothyroidism; this is a type of autoimmune disease in which my immune system was attacking my thyroid gland, so it wasn’t producing enough thyroid hormone. My dysfunctional thyroid led to a slow metabolic rate, the symptoms of which included being tired and putting on weight very easily. Although I was not yet thirty, I had a body more like that of a declining sixty-year-old.

  The root cause of this pain, lethargy, and obesity was inflammation. I got hit especially early and hard by it, but inflammation affects all of us to some degree and more as we age. If you pay attention each morning, you’ll notice that the size of your belly sometimes grows overnight—that’s inflammation. The same type of swelling happens in your brain; you just can’t see it. These changes are caused by cell-signaling molecules called cytokines. Researchers discovered them in the 1950s, but only within the past couple decades have they began to understand the link between inflammation and cytokines—specifically, a group of them called (of course) inflammatory cytokines,4 which are present throughout the body.

  While all that was going on inside of me, I just wanted to live a normal life. I was worn out by my endless diseases and by the emotional baggage that comes with having so many health problems. But it was becoming increasingly obvious that if I didn’t do something to change the trajectory of my health, things weren’t going to end well; the time had come to take action. My first step was admitting that all of the solutions that were supposed to help me lose weight (such as low-fat diets and chronic cardio exercise) weren’t doing anything for me.

  I spent four years immersed in research. The first place it led me was to the Atkins diet, more generally known as a ketogenic diet, which emphasizes cutting sugar and carbs while consuming protein and fat in order to get the body into a state of ketosis. It’s the grandfather of the modern keto diet, which still suffers from many of the limitations of the Atkins diet. That’s because it doesn’t fully address the issue of inflammation. But it got me started on a better path. I lost 50 pounds in the first three months of what would now be labeled a “dirty keto” diet. It was like a miracle.

  Losing the other 50 pounds took me ten years. Why? Because those first 50 pounds were fat, but dieting to eliminate the fat didn’t address the much more intractable problem of inflammation. Without knowing it, I was eating ketogenic foods that were also inflammatory. Nobody told me about kryptonite. Learning how to get rid of inflammation through fasting was a whole other journey for me. (News flash: when you’re eating nothing, you’re also eating nothing inflammatory.)

  Even now, a bunch of the modern keto evangelists cling to the same flawed philosophy of the Atkins diet. The dirty keto diet allows, or even encourages, eating highly processed, highly packaged foods just to stay in ketosis. Anything that’s not a carb is keto, which means that wheat gluten (which is protein) qualifies as keto on this diet. Vegetable oil is keto, too. Technically speaking, that’s absolutely true. The problem is, wheat gluten and vegetable oil make you fat. Gluten also causes inflammation, and there’s some evidence that vegetable oil can, too. Both of them make you hungry. Seed oils definitely cause inflammation, as I noted earlier. There’s a common perception that eating any kind of fat for fuel on the ketogenic diet is healthy, but if the fat you’re consuming is inflammatory, you defeat the purpose.

  Fasting provides an easy framework for not only when to eat but also what to eat. You can have your morning coffee with MCT oil and butter. You will not be eating gluten and vegetable oil and processed foods. You will be giving your body a break from inflammation and all of its associated health problems. Heart disease is actually more strongly associated with inflammation than with cholesterol level. Coronary disease accounts for an estimated 31 percent of global mortality, according to the World Health Organization5—and long periods of time without food have been shown to reduce the risk of developing it by lowering blood pressure and triglycerides in addition to inflammation.

  This point bears repeating: fasting reduces inflammation, improves health, and boosts your self-control no matter what kind of eating regimen you prefer. It will help you out if you’re on dirty keto, if you’re vegan, or if you’re living on a pizza and nachos diet. Still, I’d prefer that you eat clean if you’re going to stay in ketosis. You’ll see better results, reduce inflammation as much as possible, and you’ll just feel better.

  How can you tell if your body is inflamed? The short answer is: if you’re eating a typical modern diet full of processed foods, you’re inflamed on some level.
The most dangerous forms of inflammation—such as an inflamed brain, heart, or liver—can be hard to detect with the naked eye, but some inflammation is visible right on the surface. Take a look in the mirror. Do your love handles change from day to day? That’s inflammation. Is your skin puffy or full of acne? That’s inflammation. Is your grip weak, or are your joints or back sore when you wake up? That’s inflammation, too.

  After I lost the weight, I needed to find a way to keep it off. That meant I had to win the battle against inflammatory foods. The problem was, I didn’t know which foods were making me inflamed, and back then there was limited research available to guide me. Despite my best efforts, I was still suffering from inflammation. I could see it in the puffiness of my muffin top. I could feel it when I woke up with aching joints that made it painful to walk.

  I dialed in on the causes of inflammation. I took a good hard look at every single thing I ate and researched how it affected my body. I did day-to-day comparison tests on myself when necessary. I learned how to turn off my hunger by not eating certain foods, and that knowledge was the basis of The Bulletproof Diet. And along the way I discovered intermittent fasting.

  Well, no one alive today actually discovered intermittent fasting; it’s been a part of our species for as long as we have been a species. It’s just that I discovered how it worked for me, and I did discover that using coffee with butter and MCT oil produced extremely powerful results, better than fasting alone when I started out. I’m pretty sure no one else alive or dead had hit upon that weird combination!