Fast This Way

by Dave Asprey

  Pushing through is exactly what I worked on that night. I closed my eyes and finally fell asleep as the fire at the cave entrance died down. By then, something was definitely changing inside me. I was buzzing with energy even as my eyelids drooped shut.

  Two hours later, in the middle of the night, a loud rustling noise abruptly woke me from my deep slumber. This time, the noise was very real, not something conjured up by my lizard brain.

  THE CHEMICAL EQUATION OF YOU

  Fasting is a spiritual process. Fasting is a chemical process. There is no contradiction between these two ideas. They are both valid and equally true.

  Whether or not you consider yourself a spiritual person, intermittent fasting will shift your mood and your perceptions in ways that will enable you to look at your life differently. Those mood and perceptual shifts are the result of chemical processes in your body, but they are not chemical experiences. You could say the same about pain and fear or about love and pleasure. An experience is something that arises out of your conscious existence, and consciousness arises out of the chemistry of your brain—but nobody knows how that happens. Your molecules and your mind live side by side inside your head. How the two are connected is perhaps the greatest mystery in all of science.

  David Chalmers, a philosopher at New York University, summed up the absurd situation in an influential paper titled “Facing Up to the Problem of Consciousness.” In it, he wrote, “It is widely agreed that experience arises from a physical basis, but we have no good explanation of why and how it so arises. Why should physical processing give rise to a rich inner life at all? It seems objectively unreasonable that it should, and yet it does.”1

  Fortunately, we don’t need to understand exactly how we think in order to do it. Humans have been thinking quite effectively for the past 300,000 years without having a theory of consciousness. Likewise, we don’t have to understand every detail of the relationship between molecules and mind to know that one affects the other—and that intermittent fasting can do wonders for both. Fasting improves your focus and slows the aging process. It promotes autophagy and detoxification, helping your cells get rid of their built-up waste. And yes, it opens the path to great spiritual journeys, if you want to go there.

  All through this book, you’ve learned about various biohacks that make fasting less painful, more pleasurable, and above all more enriching. A lot of them involve being disciplined about what and when you eat. But we can get even more detailed and targeted than that. To get the most out of your diet—to give the most effective kick to both your molecules and your mind—you will want to make sure that your body has the right supply of the stuff it needs to repair itself, things such as vitamins, minerals, amino acids, and other vital compounds. That is: you will want to take supplements.

  At this point, there are several questions people usually ask. The first is some variation of “Why do I need supplements if I eat a balanced diet? I get my nutrients from food, just like our ancestors did.” The answer to that is simply that if you are planning to get your nutrients from only what you eat, it will work, as long as you also get toxins only from Mother Nature. And of course, that’s not possible. The reality is that the environment we live in is full of thousands of synthetic chemicals and stressors that we did not evolve to handle, along with natural chemicals that are processed and concentrated by Big Food in novel ways, not to mention global diseases such as COVID-19 that can travel more quickly than ever before. Your body needs more nutrients than you can get from food alone to handle that toxin load.

  There is also the question of whether food really has the same nutrients it used to, and the answer is a resounding “no!” That’s because we have depleted our soil by growing monoculture plant crops without rotating grazing animals, by spraying crops with glyphosate (an herbicide used to kill weeds), and by using industrial farming practices. There are countless studies comparing the nutrient level of modern foods to their levels fifty years ago, which have shown that overall, food—even organic food—is not as nutritious as it used to be. The final reason is even more apocalyptic than losing our soil: it’s the rising level of carbon dioxide, or CO2, in the air. We all learn in elementary school that animals breathe oxygen, and plants breathe CO2. What happens when plants have a lot more CO2? They grow more quickly, which means they get bigger, but they have less time to concentrate minerals from the soil. This transformation is already affecting food quality.2

  You are also likely to need supplements to balance out the effects of fasting. If you’re doing intermittent fasting, you may be consuming the exact same number of calories you normally do and getting the same amount of nutrients you usually do. But what if you actually eat fewer calories because you’re less hungry? What if you fast for longer periods? If you eat less food, you will get fewer nutrients—that’s just simple math.

  People also ask, “Will I still get the full benefits of supplements if I take them while I’m fasting? And won’t taking those supplements effectively end my fast?” There are no black-and-white answers here, but there are reasonable answers based on what we think we know about how the body works. Whether or not you ought to take a specific supplement during your fast depends on what it is and on how your body normally responds to it when you are not fasting. For example, some vitamins have to be taken with food. Usually, that’s either because the vitamin is fat soluble (the body is better able to absorb it when fat is also present), or it’s because you’ll feel sick if you take it on an empty stomach.

  There are two good strategies here for the “take with food” supplements. One is to simply stop taking them, which works fine. You probably won’t die if you miss a few days of supplements, so you can go on a “supplement fast” along with avoiding food. Regardless of whether you’re fasting or not, there’s a case for occasionally mixing up or skipping what you take. It’s that you don’t want your body to get metabolically lazy by downregulating its own production of protective compounds; this is another example of how the body hates consistency. The other strategy is to do what I do: take some supplements that require food even when I’m when fasting, knowing I’ll still absorb some of the compounds. The problem is that no supplement company on Earth writes “Take with food or you will barf” on the label, so it’s hard to know why it says to take a supplement with food.

  It’s quite easy to figure this out—take a few of your supplements on an empty stomach. If you feel as though they’re going to come back up, break your fast right away, which will stop the nausea. There, now you know which supplements not to take on an empty stomach. There are some guidelines for you below. No one wants to taste vitamins a second time.

  Making things more complicated, some supplements have additive effects when they’re taken together, such as vitamins A, D, and K2. You can take vitamin K2 any time of day. Vitamin D is best taken in the morning, or at least before noon, because it is a circadian hormone that helps to wake you up, and with a meal, because it is fat soluble. Vitamin A is best taken with meals because it is fat soluble. You see how this goes: if you are dosing up on all three vitamins together, you’ll get the biggest bang for your buck by taking them in the morning with a meal.

  But wait; most people who read this book and try intermittent fasting will be skipping breakfast most of the time, just because they feel a lot better doing so. How are you going to take your morning fat-soluble vitamins D, A, and K2? Especially while there’s a novel coronavirus running amok, you must manage your vitamin D levels. This combination of nutrients powerfully supports your immune system, bones, and cardiovascular system. Your best bet is to take them on an empty stomach, knowing that they may not absorb as well but will still absorb. You could also take them when you break your daily fast. Since I have Bulletproof Coffee most mornings, with enough fat in it to stimulate nutrient absorption, I take my supplements with it. On mornings when I have black coffee, I take them, too—and I have quickly learned which ones you really don’t want to take on an empty stomach. After a
little while, you will learn to fine-tune your fasts, figuring out which eating rhythms, foods, and supplements work best for you.

  BEWARE OF THE BARFY FOUR

  Some supplements will reliably ruin a fast. Not because they’ll change your metabolism but because of what they do to you on an empty stomach. I call them the “Barfy Four.” Do I need to say more?

  The first of the Barfy Four supplements to watch out for during fasting is the B vitamins. If you want to experience the worst ever day of fasting, start out with a B complex on an empty stomach. If you can keep it down, you’ll taste it all day and wish you hadn’t, but most people get nausea from it. Steer clear of B complex. However, vitamin B12 is an important supplement, and the lozenges or capsules don’t cause nausea in most people.

  The second way is multivitamins. All-in-one pills often contain low-quality formulations of vitamins, and they contain B complex. To top things off, multivitamin pills are typically manufactured with fillers and additives that are difficult for the body to absorb, so you may not even get the benefits of the active ingredients. To be honest, avoiding multivitamins is good advice in general. You simply can’t fit a meaningful dose of a useful number of vitamins or minerals into one or two capsules, and what you get is sometimes worse than nothing at all. That certainly is true during a fast.

  The third is fish oil. This is a marvelous supplement, and you can take this one with Bulletproof Coffee. If you take it with black coffee or an empty stomach, though, you’ll probably feel nauseated. Plus, you will taste it all day. Pro tip: if you get nasty fish burps from your fish oil, it is likely rancid. Go for a great brand that doesn’t have a strong flavor.

  Finally, you can count on iron supplements and multimineral supplements to cause nausea, acid reflux, or both. Most people can handle single minerals, such as magnesium or zinc, without a problem on an empty stomach. Bundle a bunch of them together, and it’s a different story.

  When considering how to approach supplements during a fast, it’s important to consider the reason you’re fasting to begin with. If you are fasting for weight loss or energy or spiritual reasons, you can do what you want. But if you’re looking to allow your gut to rest and heal, avoid most if not all supplements. Even if they are formulated well, multivitamins disrupt a gut-rest fast. You should also avoid prebiotic fiber and C8 MCT oil during a gut rest fast. You’ll still want to make sure you’re consuming some electrolyte minerals, including magnesium, potassium, and sodium. If you’re working with a functional medicine physician on gut healing, you’ll probably have some herbs to take, too.

  As for the question of whether you’re cheating on your fast if you take supplements, the dogmatic fasting purists will tell you that anything other than water breaks a fast. In this case, they simply do not understand the true meaning of fasting, going without. You can have Bulletproof Coffee without breaking your fast if you’re fasting for metabolic reasons, antiaging reasons, or energy. I believe that you can take supplements, too. You’re still in going without mode. That said, be aware that some supplements, especially drink mixes, contain sugar. During a fast, you want to limit yourself strictly—no more than 20 calories a day from sugar and ideally none.

  There are a couple things that you absolutely must avoid during a fast. One is proton pump inhibitors—these drugs block stomach acid production, and you’ll probably have a hard time digesting food at the end of a fast if you block this important digestive function with drugs. If it is a prescription, ask your doctor about skipping a day or three. Another thing you must avoid is food additives: artificial colorings, flavorings, MSG, and sweeteners. They wreck your gut bacteria and often cause intense cravings.

  Here’s the bottom line. In general, you can take vitamin and mineral supplements during an intermittent fast and still get full fat-burning benefits. You have to be more restrictive if you want to do a gut rest as well. And you should be informed about the specific effects of the supplements you’re taking, because some of them can affect your body’s function during your fast. For instance, they can:

  Decrease your blood sugar, possibly zapping your energy and giving you brain fog

  Raise your glucose level, taking you out of ketosis (the whole point of fasting)

  Pass through your body without as much being absorbed as when they are taken with food

  Make you nauseated if you take them on an empty stomach

  Taking vitamins and supplements while doing intermittent fasting requires some experimentation. When you fast, you will probably experience more sensitivity to your supplements. It’s possible that you will get really tired or will experience intense hunger and cravings after you take your supplements—if so, they’re probably not working for you. Time to mix things up.

  To be honest, every aspect of fasting requires you to be aware of your state. Being Bulletproof is all about paying attention to how your body feels and adjusting accordingly. To help you out, I’ve broken down some of the major classes of supplements that you should consider and summarized their effects.

  THE SUPPLEMENT CHECKLIST

  ACTIVATED CHARCOAL

  * * *

  This is the number one supplement I suggest taking during a fast, yet most people overlook it. It isn’t sexy, I guess. Activated charcoal is a black powder made of coconut shells, peat, sawdust, olive pits, or bone char. (The charcoal I designed for Bulletproof uses only coconut and is the finest-size particle to maximize effectiveness.) It is heated to extremely high temperatures, which makes it more porous than regular charcoal. It’s quite different from the briquettes you use on your barbecue. Activated charcoal has a huge surface area—1 teaspoon of it has a surface area the size of a soccer field!—and a negative electrical charge that draws positively charged toxins toward it. It traps toxins and chemicals in your gut, preventing them from being absorbed into your bloodstream. Instead of these poisons becoming a part of whatever fat you’re carrying around, they leave your body as waste products.

  Getting rid of the toxins floating in your body will slow the aging process and help you think more clearly. Fasting alone will give you a detox, but activated charcoal will help. In fact, studies show that activated charcoal extends life span even if you aren’t fasting. It also absorbs stress-producing chemicals produced by bacteria in your gut, reduces cholesterol, and promotes kidney function. Here’s one more really cool thing about activated charcoal: it will reduce the severity of your cravings during your fast. It’s startling: you get cravings, you take charcoal, and now you don’t feel hungry anymore. What’s going on? The bacteria in your gut are freaking out because they don’t have any food, either, which causes them to produce lipopolysaccharides and various toxins that give you physical stress. You interpret that response as emotional stress, which in turn can trigger cravings and irritability. Activated charcoal cuts that cycle off at the foundation, so you can happily go about your fast.

  A small downside is that activated charcoal can make you a little bit constipated. That’s not going to be a major problem during fasting, since you’re not moving food through your body anyway. It also absorbs any medication you take at the same time, so be careful.

  Daily dose: 1 to 10 1,000 mg capsules, away from medications, fewer if you get constipated. Any time of day or night.

  SYSTEMIC PROTEOLYTIC ENZYMES

  * * *

  Your body makes enzymes to speed its biochemical reactions. Proteolytic enzymes break down proteins; you use them when you eat protein. But systemic enzymes are not enzymes that are meant to act on your steak; they’re meant to act on you. If you’re trying to crank up your body’s self-cleaning autophagy, take these enzymes. They are normally produced in the pancreas, but if you take them as supplements, you can boost your enzyme levels and give your pancreas a rest. Proteolytic enzymes break down unneeded proteins in the body as part of the general process of flushing out cellular junk. The two most popular forms of these enzymes are serrapeptase and nattokinase. Serrapeptase is made by silkworms, which use th
e enzyme to dissolve their cocoons after metamorphosis (that’s how we discovered it!). Thankfully, now it’s made by fermentation. Nattokinase is derived from fermented soybeans, a particularly unappetizing, slimy, nutty dish you might find at a Japanese restaurant called natto. Proteolytic enzymes are great for cardiovascular health. They also help break up clotting factors (which can cause dangerous blood clots) and scar tissue in the body, as well as remove worn-out immune molecules from your blood.

  There are also animal-based systemic proteolytic enzymes. For me, these are the gold standard, because they are broader spectrum than the plant-based ones. There are several different brands of proteolytic enzymes that aid digestion. Wobenzym and Masszymes are good ones. If you’re going to be fasting and you’re saving money by not eating, you might as well splurge on proteolytic enzymes. They promote optimal nutrient digestion and absorption, which are key to gut health. They tell your body, “Hey, you got everything you need. Just go work on yourself. Fold some proteins. Get rid of some dead stuff. Do your job.”

  You feel better. Your blood flow improves. It’s a good move. I therefore tend to take a very high dose of proteolytic enzymes when I am fasting. When I was recovering from being obese, I sometimes took one hundred capsules a day on an empty stomach; they are considered safe, but the normal dose is 1 to 4 capsules. I have been taking at least 10 high-dose (120,000 SPU each) serrapeptase supplements while fasting for ten years, along with six animal-based proteolytic enzymes. They are a waste of money to take if you have food in your stomach.