Fast This Way Summary and Review | Dave Asprey

How to Lose Weight, Get Smarter, and Live Your Longest, Healthiest Life with the Bulletproof Guide to Fasting

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Introduction

Have you heard of intermittent fasting and thought, “that’s not for me”? 

Fast This Way attempts to change your mind. This best-selling book uses the latest nutritional science to reframe intermittent fasting. Instead of just looking at this practice as a way to cut calories, fasting can be a tool to hack your biology.

Unlike other books on fasting, this book reads more like a how-to guide. You’ll get actionable advice to make fasting achievable and sustainable.

About Dave Asprey

Dave Asprey is the author of four New York Times best-selling books. You may know him better as the author of The Bulletproof Diet and Super Human, the inventor of Bulletproof Coffee, and the founder of Bulletproof Nutrition, Inc.

Asprey holds an MBA from the University of Pennsylvania. During his career, he held executive-level positions at tech startups, including Trend Micro and Citrix Systems.

He is also known for his early venture into e-commerce. In 1994, Asprey started selling t-shirts with caffeine molecules printed on the front. He worked out of his college dorm and expanded his business to serve customers in twelve countries.

Asprey is one of the original lifestyle gurus and the father of biohacking. “Biohacking” is the practice of using oneself as a real-life experiment to study different ways of improving health.

As a biohacker, Asprey has spent his life experimenting with alternative diets and lifestyles. One such diet is the subject of this book: intermittent fasting.

StoryShot #1: Fasting Is a Psychological Battle

Asprey opens the book by recounting his visit with a shaman. He sought her out to guide him on a fasting journey. During his journey, he experimented with many types of fasting.

Ultimately, fasting helped Asprey discover the difference between hunger and craving.

“Hunger is a biological message and is something you can control. Craving is a psychological need and is something that tries to control you”

– Dave Asprey.

He learned that denying his cravings helped him feel more in control and have power over his relationship with food. Going without food for limited periods helped him feel less dependent on it. 

But reaching this point isn’t easy. That’s because fasting is all in your mind. If you think you can’t do it, you’re listening to your cravings, not your hunger.

Hunger is a physical thing. Your stomach growls, you may feel woozy, and your ability to focus may suffer. Hunger and its symptoms mean your body needs to fuel up on some highly nutritious foods.

Cravings, however, could have a physical and psychological aspect. You can have a craving even if you aren’t hungry. Cravings direct us to eat certain ingredients or foods with specific textures.

Scientists are still debating the physical versus psychological aspects of cravings. For example, the body craves ingredients it’s missing. On the other hand, scientists believe cravings have more to do with behavior.

The research will eventually uncover the truth here. Fasting forces us to overcome cravings. Instead of eating at every whim, we wait until we truly feel hungry.  

“Fasting allows you to think clearly about those choices, because it heightens your awareness. It puts you in control of your biology. It lets you make your own rules.”

– Dave Asprey.

The difficulty of fasting comes from denying those cravings. Cravings are likely psychological, fasting is about your mindset.

StoryShot #2: Understand The Molecular Biology of Fasting

Dave Asprey may not be a scientist, but he still spends an entire section discussing the biology of fasting.

For decades, diet culture has harped on about weight being all about what you eat, and how much you eat. Yet more recently, studies have shown that timing is also a factor in how our bodies respond to food.

Eating habits have changed significantly over the last 50 years. While three meals a day used to be standard, the average adult now eats about six times a day. Some adults eat up to 15 times in 24 hours.

This fact and the worsening obesity epidemic in western cultures have led scientists to study this phenomenon. Some nutrition experts have found that not giving our bodies long enough breaks between meals is unhealthy for us.

A commonly touted line of evidence is evolution. Early humans did not eat multiple meals a day. Instead, they evolved with short periods of fasting.

“The history of human evolution is also the history of food. It’s the history of fasting, too. Our bodies and brains are inherently adapted to it.”

– Dave Asprey.

Humans have always been diurnal. This means we are awake during the day and asleep at night. Yet, these days, more and more people stay awake late into the night, providing more opportunities to graze.

According to research, this behavior throws modern humans’ metabolism out of sync. Obesity correlates with extended and excessive eating. It is these eating habits that affect our overall health.

This is where intermittent fasting can come in. Intermittent fasting restricts eating to three to five times a day during a 12-hour window. Ideally, this 12-hour window should take place during daylight hours.

The Potential Health Benefits of Fasting

So, what’s all the hype about intermittent fasting? Fasting may have the power to do the following:

• Support weight loss
• Heal your gut
• Induce autophagy–the body’s ability to clean and rejuvenate cells 
• Reduce your risk for chronic diseases
• Improve insulin sensitivity
• Reduce inflammation
• Boost metabolism
• Increase endurance
• Enhance cognitive function
• Lengthen your life span

Further, studies have shown that intermittent fasting can fight certain diseases. For example, animal studies have supported fasting benefits for diabetes, cancer, and neurodegenerative conditions like Alzheimer’s.

StoryShot #3: There Isn’t Just One Way to Fast

One of the main reasons people fail at fasting is that they don’t choose the right fasting method. After all, there is more than one way to do intermittent fasting.

For instance, fasting is a common practice in many religions and may differ depending on the religious practice. For example, during Ramadan, Muslims are required to fast during the day, while Seventh-day Adventists fast at night.

You don’t have to be religious to fast. Fasting proponents have come up with three types of fasts:

1. Time-restricted or intermittent fasting
2. Alternate-day fasting
3. Modified fasting

Intermittent fasting is probably the most popular on this list. But being popular doesn’t mean this method will work for you. It requires you to restrict eating to a specific time, during which you can consume whatever you crave or are hungry for.

If intermittent fasting doesn’t work for you, try alternate-day fasting. This more extreme fasting program requires you to abstain from food and drink (except water) every other day.

Modified fasting is the third type of fasting. In this regimen, consume up to 25% of your energy needs from food for two days, then eat like usual for five days. 

Types of Intermittent Fasting

Just as there is no one way to fast, there is no one way to intermittent fast. Instead, people have come up with multiple time-restricted fasts. 

“The more you mix things up and the more you reject consistency, the stronger and more flexible your cells will be. They will no longer be trained to crave one particular snack or comfort food.”

– Dave Asprey.

One of the most popular intermittent fasts is called the 16/8 method. This diet requires you to fast for 16 hours. Then, you can eat whatever you want during the remaining 8 hours, which should ideally take place during daylight hours.

The Warrior Diet is another form of intermittent fasting. This program allows you to eat fruit and vegetables only during daylight hours. At dinner time, you are allowed one large meal.

You could theoretically develop your own intermittent fasting diet. However, always talk to a physician before significantly decreasing your caloric intake.

StoryShot #4: Fast for A Longer Life 

Hunter-gatherers would roam the plains searching for wild game. Often walking miles at a time. When they finally caught an animal, everyone shared the feast. Rarely did the meat last more than a few days. When the food was exhausted, they would hunt for more and subsist on a few edible plants. Until the next meal, everyone went hungry, no one died from going a few days without food. 

Fasting unleashes your hidden evolutionary powers. But social structures and the food industry keep telling us to eat regular meals, regardless of whether we are hungry or not. We keep craving food all the time, and we face an obesity pandemic.

The Price of Plenty

Living in the era of abundant food, most of the world does not need to worry about famine and starvation. The trade-off is the loss of fasting along with the benefits. Mark Mattson, a neuroscientist at Johns Hopkins University and former head of the Laboratory of Neuroscience at the National Institute on Aging, sums up the dilemma in a 2014 review article, “As a consequence of the modern ‘couch potato’ lifestyle, signaling pathways that mediate beneficial effects of environmental challenges on health and disease resistance are disengaged,” he continues, “Reversal of the epidemic of diseases caused by unchallenging lifestyle will require a society-wide effect to re-introduce intermittent fasting, exercise, and consumption of plants.” 

Food for the Brain

Fasting makes you sharper. If you skip eating for 24 hours, your senses will be more finely tuned, and your awareness will be heightened. The fewer toxins in your system, the higher your ability to reason. The energy consumed for digestion is now used for optimal brain functioning. 

Valter Longo is a gerontologist at the University of Southern California whose research focuses on biochemical markers for diabetes. According to Longo, fasting reprograms the brain’s metabolism and helps clear out malfunctioning cells, including self-destructive immune cells that cause multiple sclerosis. 

It is hard to believe that the body can benefit so drastically from fasting. However, looking back on evolution, the body is packed full of repair and rejuvenation mechanisms. All fasting does is remove dietary impediments. 

“Fasting puts us in control of a 4-billion-year-old evolutionary process.”

– Dave Asprey.

StoryShot #5: Fasting and Sleep Have a Bi-Directional Relationship

Did you know that people who get less or low-quality sleep crave more high-calorie foods? 

Getting enough quality sleep is one key to successful intermittent fasting. Poor sleep can affect your appetite. Sleep loss makes your nose smell scents differently.

For example, a study of 25 healthy people tested the effects of 4 hours and 8 hours of sleep. Four weeks later, the 4-hour group reported feeling hungrier. They were hungrier for high-fat, high-sugar food like donuts.

Yet, the opposite is also true. What and when you eat affects how well and how long you sleep.

The ideal time to digest food is during the day. At night, our bodies stop secreting as much insulin, which reduces our ability to digest sugars. Nighttime is when our bodies digest saturated fats (aka cholesterol).

If you eat too close to bedtime, this can throw your body’s metabolism out of sync. This can affect your ability to get a good night’s rest. It can also cause your body to store more fat. 

“Ideally, you should always leave at least three hours between your meal and the time you go to sleep.”

– Dave Asprey

Asprey’s Tips for Getting a Better Night’s Sleep

Aside from not eating right before bed, how can we ensure a good night’s sleep? Here are some top tips from the book:

• Go to sleep around the same time each night and wake up around the same time each day.
• Don’t use electronic screens before bed because the blue light can throw off your Circadian Rhythm.
• De-stress before bed with meditation or mindfulness.
• Avoid alcohol and cigarettes.
• Don’t drink caffeine for at least five hours before going to bed.

Of course, you should also ensure you get the right amount of sleep each night. Adults should get at least seven to eight hours of sleep every night.

StoryShot #6: Fasting Can Help You Get Physically Stronger

Other benefits of intermittent fasting include weight loss and muscle gain.

Taking longer breaks between meals and eating during the day can lead to increased lean muscle mass. Both practices can improve your metabolism, enabling your body to burn more fat.

Plus, intermittent fasting can put the body in ketosis. Ketosis is the idea behind the popular Keto Diet. This natural process pushes your body to burn fat for energy instead of carbohydrates.

In one study, researchers compared muscle gain between men on a normal diet and men who engaged in intermittent fasting. At the end of eight weeks of working out, the non-fasting group put on weight, while the fasting group did not.

You can also expect muscle gain if you add in exercise during your fast. Research has shown that people who diet lose more muscle mass than people who use intermittent fasting programs.

StoryShot #7: Fasting Can Help You Feel Mentally Stronger

Fasting can make you feel stronger mentally. Fasting puts stress on the brain and body. But our brains are highly adaptive. They increase the production of mitochondria in response to this stress.

Asprey has written on mitochondria previously. The book Head Strong explains how mitochondria can play a role in preventing aging. In this book, we learn about mitochondria in terms of their role in the brain.

Specifically, mitochondria help brain cells make energy. They also increase the formation of synapses, which supports brain cell communication.

What does all this mean on a behavioral level? Fasting can give you more focus and help clear your mind. Improved communication between brain cells means you can think more clearly and problem solve more effectively.

There are also studies that show the benefits of fasting for brain diseases. Researchers have found that fasting can help with symptoms of diseases like Parkinson’s and Alzheimer’s. There’s also proof of fasting effects on epilepsy, multiple sclerosis, autism, stroke, mood disorders, and anxiety.

StoryShot #8: Support Your Fast With Supplements

Intermittent fasting comes with calorie reduction. Restricting your calories could mean you miss some essential nutrients. Many people who fast report being deficient in vitamins and minerals.

You should take supplements while you fast to avoid this issue. Asprey says that using supplements during the hours or days when you’re fasting can keep you feeling strong. However, some supplements can break your fast as you have to take them with food. This includes amino acid and fatty acid supplements, fat-soluble vitamins (e.g., A, D, and K), magnesium, iodine, zinc, and copper.

Other supplements don’t require food. This includes the following:

• Creatine
• Electrolytes
• Probiotics and prebiotics
• Water-soluble vitamins (e.g., B and C)

Taking supplements doesn’t just help you get the nutrients you need. Some supplements may also boost your body’s ability to burn fat while you fast.

StoryShot #9: Women Should Fast Differently Than Men

Men and women are biologically different, so fasting affects the genders differently. Women are more sensitive to the effects of fasting.

Women need to undergo less frequent and shorter bursts of fasting. Why? Because fasting can impact women’s hormones.

Fast This Way recommends that women only fast for up to 14 hours a day. Men can fast for up to 16 hours in a 24-hour period. Women can fast for up to 16 hours a day, but only if they fast every other day or so, and not for a full week.

Studies show that the longer women fast, the lower their insulin levels. This can lead to poor blood sugar control.

Pregnant and breastfeeding women shouldn’t fast, and neither should those with a history of eating disorders.

StoryShot #10: You Won’t Be Hungry If You Fast the Right Way

In the final section of Fast This Way by Dave Asprey, we learn how to implement all these lessons. Here are some of his general recommendations for fasting:

• Fast for 12–16 hours, depending on your gender, health status, lifestyle, and hunger patterns
• Eat 2–3 meals per day, including breakfast
• Eat your last meal before 4 p.m.
• Do not snack after 4 p.m.
• Try to increase the protein content of each meal, especially focusing on plant-based sources of protein

Avoid eating too many carbohydrates, as these can destabilize your insulin levels.

You can have coffee and tea during your fasting hours. Bone broth is another good way to keep yourself satiated while you’re fasting.

The only food you should try your best to avoid during fasting hours is protein. Proteins trigger hormones in the body. Hormone production takes a lot of energy.

If your body needs all that energy to produce hormones, you’re more likely to feel hungry. Temporarily starving your body of protein can lead to autophagy, the body’s ability to clean itself of dead and damaged cellular debris.

Asprey warns against using these as hard-and-fast rules. He says even he breaks his fast once a week to have brunch with his family.

Final Summary and Review of Fast This Way

Fast This Way by Dave Asprey is essential reading for anyone interested in fasting. Asprey explains the science behind this practice and the incredible benefits associated with it. Plus, he offers multiple personal anecdotes about how intermittent fasting changed his life and his health.

If you’re looking to lose weight, sleep better, feel mentally and physically stronger, and live longer, this book can help. It offers a blueprint for men and women to follow to fast without harming the body or feeling hungry. Pick up this book if you want to change your life as Dave Asprey did.

Before you go, here’s a reminder of the key points you need to remember from Fast This Way:

• Fasting Is a Psychological Battle
• Understand The Molecular Biology of Fasting
• There Isn’t Just One Way to Fast
• Fast for A Long Life
• Fasting and Sleep Have a Bi-Directional Relationship
• Fasting Can Help You Get Physically Stronger
• Fasting Can Help You Feel Mentally Stronger
• Support Your Fast With Supplements
• Women Should Fast Differently Than Men
• You Won’t Be Hungry If You Fast the Right Way

“Fasting from food is an entry point into an enormous, powerful world of honesty and control. As soon as you stop hiding in one part of your life, all kinds of other possibilities begin to open up. That’s why I’ve written this book. It’s not about helping you fit into your bathing suit or reducing your risk of atherosclerosis- though they certainly are nice bonuses. I want to invite you to open up the possibility of radical self-improvement.”

– Dave Asprey.

Rating

We rate this book 4.3/5.

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