Compared to any other health supplement, research on intermittent fasting is scarce. After all, there is little money in telling people to eat less often. The bit of data that exists is very clear, however: intermittent fasting (IF) is extremely healthy no matter what your health goals.
Most people have found intermittent fasting as a method of losing fat and gaining muscle. Indeed, there are tremendous hormonal changes involved with intermittent fasting that can allow practitioners to gain lean mass, but the anti-aging and disease prevention aspects are as important if not more so. While there may be some other intermittent fasting guides, this is my ultimate guide to this practice.
First, I’ll explain how you can get started even if you have no experience. Then I’ll detail the scientific research to help you determine whether it is something you would like to pursue. This is going to be a long one so grab some…tea!
Stop Eating and Start Living
The concept of intermittent fasting is not one that most people are willing to try. I’ll admit, willfully depriving yourself of food seems like a bad idea when you are hungry. As I’ll explain in more detail later, the only reason you feel regularly hungry is because of the expectation of food and the choices that you consume. Understanding this will allow you to easily start with intermittent fasting and overcome the first few weeks of moderate unpleasantness. Here are some methods you can use in order to start intermittent fasting, which have helped me very much:
1. Start with one day
Intermittent fasting is no different than anything else. If you consider doing IF for the rest of your life, it will seem daunting. Just tackle the first day and you will realize that it is not that bad to eat only 4 – 8 hours a day. With a single day on your belt it is infinitely easier to move to day two, three, and before you know it you will be fasting normally.
2. Determine your goals
Before you start an IF protocol, you should determine your goals. If you want to use it for body composition (i.e: fat loss, muscle growth) purposes, then you can do a Lean Gains style 16 hour fast with an 8 hour feeding window every day. If you would prefer to practice IF for anti-aging and disease prevention, you can even get away with 36 hours of fasting. It all depends on what you are looking to do, but remaining under 72 hours is recommended.
3. Time your IF for social purposes
Technically, you can do an intermittent fast from 9:30 am until 5:30 pm. With this schedule, you will not only eat more meals and calories, but you will probably cheat more often. Consider social situations and the temptation to eat dinner later than 5:30pm. I make it easier on myself by allowing my 8 hour feeding window (when I eat) from 12pm – 8pm.
4. Wake up and drink water
If you choose the IF protocol that I advocate, fasting overnight and then until 12-2pm, then it is a good idea to overcome hunger in the morning with a few choice methods. First, drink water as soon as you wake up. It may not seem like it, but your body is naturally dehydrated while you sleep. Ensure you replenish the water as soon as you wake up and the feeling of hunger will slightly dissipate.
5. Fasting is better with tea / coffee
When I fast in the morning, I make sure to drink a little bit of tea. This will not break the fast so long as there is no additional sugar or cream. Drink it warm and straight and it will help to focus and remove any hunger pangs.
Some people, including prominent biohackers like Jolly and Dave Asprey, enjoy Bulletproof® coffee. This formulation includes coffee, MCT oil, and butter. The ingredients offer a lot of calories that the body can burn as fuel, but without disrupting essential bodily functions, such as cell repair. I have yet to try it, but many endorse it. It will definitely make the start of your fast that much easier.
6. You won’t be hungry forever
The hormones that inform hunger are based primarily on habit more than anything else. The reason you are hungry during the morning is because you are used to eating then. After a few weeks, (approximately 4 or less) you will not be hungry at all during your fasting periods. Within the first week, the hunger should dissipate. Knowing that you will not have to live with hunger forever is a great way to begin from a psychological perspective.
7. Choose a day to indulge
Some people consider it wise to have a “cheat day” consisting of whatever foods you would like. I am a staunch opponent of such days, but I do have higher calorie / carbohydrate days as well. My days include 85% dark chocolate, almond butter, and more sweet potatoes, which are all healthier / cleaner sources to indulge upon.
8. Stay busy while fasting
One of the reasons it is so easy to fast overnight is because you are sleeping. If you are awake, make sure you are staying busy as best as you can. At the beginning you are not going to help your cause if you focus on your lack of food!
9. Food choices matter
You may find intermittent fasting to be a great way of easily improving your health, but none of it will matter if you do not properly eat during your feeding window. I advocate (and practice) a low-carbohydrate, mostly Paleo style diet that is high in fat and protein. I was raised as a vegetarian for 20 years. So no, I’m no steak and potatoes hillbilly.
10. It isn’t for everyone
Don’t make the mistake of thinking that intermittent fasting is for everyone. See how you feel for a few weeks and determine whether the practice is right for you. Sure, there is plenty of evidence that it is a healthy and optimal practice, but for some people it just doesn’t work. My health conscious friend Madelyn has tried to no avail. Don’t feel let down if you would rather not pursue it!
Pregnant or breastfeeding mothers should probably not fast nor should those with serious medical conditions. Speak to a doctor if you feel more comfortable with their advice.
Increased Brain Function
Now that you have some tips to get started, we will dive into the science of it all. Here at The Hacked Mind, we love improved brain function! Conventional wisdom indicates that frequent meals are the best way to keep your brain focused and productive. It’s common to see individuals consuming meals, snacks etc. to maintain the calories they need to think creatively and function more efficiently. So, how does intermittent stack up against constant / frequent consumption? Turns out, it’s much better.
In the same way reduced oxidative stress improves aging, it also improves memory. This is one of the reasons why animal studies show decreased Alzheimer’s, Parkinson’s, and Huntington’s disease. The subsequent cellular stress resistance offers the brain plenty of benefits.
One of our favorite neurotransmitters, brain-derived neurotrophic factor (BDNF), is like fertilizer for the brain. It promotes neurogenesis and increases brain capacity. Typically, BDNF increases with physical activity, but intermittent fasting has a similar impact. If you can’t get enough exercise, start fasting!
Dietary restriction, whether caloric restriction or intermittent fasting (but we love the latter!), can lead to the stimulation of new stem cells and synaptic plasticity. The connections between neurons (through synapses) are made quicker and more efficiently.
Whether you want to improve your brain function in the present so that you can make quicker connections, think more creatively, and be more efficient or just prevent brain function deterioration with age, it is a good idea to take up intermittent fasting.
There are other tools that have this neurogenesis effect as well. For example, something like cannabidiol oil has been implicated in reduced inflammation in the brain. Even the alkaloids in a microdose of ayahuasca can be profound for neurogenesis.
TL;DR: IF can improve brain function in the short term by producing BDNF neurotransmitters. They also help prevent long-term brain deterioration.
Disease Prevention, Wellness, and Aging
Diseases of civilization have become an important topic in modern discourse. Things like cancer, diabetes, and others are some of the biggest killers throughout the world and in the United States particularly. As medical care recipients far outweigh healthier individuals, the country’s medical finances are in disarray. Therefore, it is striking to find a practice like intermittent fasting that is so simple and can profoundly affect the body’s chances of contracting any of these diseases.
For diseases, such as diabetes, one of the most important factors is insulin resistance. Due to modern food abundance, it is easy to elevate blood sugar levels beyond what our ancestors could have ever done. In doing so, our hormones have fallen completely out of balance. Problems with insulin are undoubtedly the cause of most diabetes related problems. Researchers in Berkeley, CA tested calorie-restriction and a form of intermittent fasting on animals and came to startling conclusions.
Throughout the studies, fasting glucose concentrations decreased. Three studies found decreased circulating glucose concentrations after 20 – 24 weeks. In plain terms, the animals were properly regulating sugar to avoid diabetes.
In human studies, the scientists were unable to come to such conclusions. However, they did record more insulin sensitivity in patients who had undergone the intermittent fasting protocol. Even when people ate as much as they wanted during the eating window, so long as they spent 16 – 20 hours fasting, they were able to increase blood sensitivity.
TL;DR: IF can improve blood glucose levels and insulin sensitivity, which are the two biggest biomarkers of diabetes.
Poor cardiovascular performance is a result of many lifestyle factors, such as dieting and exercise. Clogged arteries are a leading factor in cardiovascular disease and elevated cholesterol (of certain types) levels often point towards a brewing storm.
A study at the University of Utah questioned 500 people who had fasted at least 1 day per month and found that they were 40% less likely to have clogged arteries. Furthermore, after only 3 weeks of intermittent fasting protocols, patients were able to see increased HDL levels (good cholesterol) and decreased triglyceride levels (bad). Decreased blood pressure in humans has not been seen, but is apparent in animals.
TL;DR: IF decreased biomarkers that point to cardiovascular disease while improved those that indicate cardiovascular health. Additionally, clogged arteries seem to be less of a problem for those with this dietary regimen.
No human cancer studies with intermittent fasting exists, but animal studies are clear: intermittent fasting decreases the likelihood of getting cancer. After only 16 weeks eating the same foods, but in restricted fasting windows, mice had a 33% lower risk for certain cancer types.
The most likely explanation, which would indicate a similar benefit in humans, is the autophagic process. Autophagy is a process that degrades damaged cell membranes. Often the process will support the death of cancerous cells, but continually eating brings the body out of an autophagic state.
TL;DR: Animal studies show a dramatic decrease in cancer after only 16 weeks of IF; largely by allowing the body to perform autophagic functions.
The Gender Gap
Between all of the studies, an interesting caveat of intermittent fasting becomes apparent. With insulin sensitivity was tested with intermittent fasting, women saw little to no improvements. For decreasing triglyceride levels, the results were the same. That does not mean women should or cannot partake in intermittent fasting, but studies seem to indicate less benefit or a higher level of health before participating.
The research regarding aging and caloric restriction is clear, but who wants to eat less? With intermittent fasting you can get many of the same benefits as caloric restriction, but while eating more of what you want.
Oxidative stress is one of the primary factors in aging and intermittent fasting can reduce the damage to your cells. The scant evidence indicates intermittent fasting decreases the markers of oxidative stress (including 8-isoprostane, nitrotyrosine, protein carbonyls, and 4-hydroxynonenal adducts) while increasing the anti-oxidants levels in the body. Again, this has to do with autophagy along with other factors.
A 1956 modified intermittent fasting study in Spain followed elderly subjects for 3 years. One of the groups had a standard diet and this resulted in 219 days in the hospital with 13 deaths over the trial. The other group with intermittent fasting included in their routine managed only 6 deaths and 123 days in the hospital. Pretty, striking right?
Hormones have a particularly important role as well. Insulin-like growth factor (IGF-1) stimulates growth and reproduction, but this drives aging even quicker. With decreased IGF-1 from intermittent fasting, your body starts to repair cells.
TL;DR: Oxidative stress, the major component in aging, is reduced through IF without the need to reduce calories consumed. Joy! Eat more delicious food! Decreased IGF-1 also allows more cell repair to take place.
More Muscle, Less Fat
If increased brain function, anti-aging, and disease prevention don’t tickle your fancy, one of the most common / popular uses for intermittent fasting is for body composition. Whether you are trying to shed a lot of weight or just remove the last bit of belly fat before summer, intermittent fasting can help. Best of all, for biohackers like myself, intermittent fasting is an “easy win”. The only thing you have to restrict is when you eat. No exhausting yourself on the treadmill or eating bland food.
Much of the body composition conventional wisdom is flawed. As the authors of Man 2.0: Engineering the Alpha are aware, theories about metabolism are wrong. While eating more often can increase the metabolic rate, the thermic effect of food is based on caloric intake rather than timing. If you compact the same number of calories in a shorter window, you’ll have the same metabolic rate and your body will be burning at the same speed as otherwise.
A study in Louisiana showed that metabolic rate remained the same and subjects lost 4 +/- 1% of their body fat as a result of an IF regimen. Others indicate an increase in fat oxidation, which is correlated to fat-weight loss.
Common sense also indicates that with a shorter window of eating, there is less likelihood of overeating. It is not only impractical, but often uncomfortable to eat too many calories / meals with a short feeding window.
Hormones of Hunger and IF
As my free book Brain Hacking 101 indicates, balanced hormones and neurotransmitters are of the utmost importance for your general wellbeing and health. Optimizing them naturally can be incredibly effective and that is exactly what intermittent fasting helps you to do with hunger and body fat storage.
You have probably never read about ghrelin, but it is one of the most important factors when trying to begin an IF regimen. This hormone is responsible for the feeling of hunger. The cells responsible for producing ghrelin operate on a circadian rhythm that is determined by meal times. Therefore, you only get hungry because of when you are used to eating, not necessary when you need to eat (within reason).
You will see a metabolic increase during short term fasting periods because your body has an evolutionary response to get off of your ass to find some food. Once you can optimize production of ghrelin, you can get by with eating less with ease.
There is always one trickster in the bunch and leptin is just that. This hormone is most responsible for thyroid hormones that regulate fat loss and metabolism. Because leptin is produced in fat stores, the less you have the harder it is to produce. This can result in stagnation, plateaus in physical fitness and body composition.
When leptin can be spiked, through the process of intermittent fasting feeding windows, it can help burn more body fat. From a body composition perspective, it is actually better to have a day with higher calories and carbs. Some promote a “cheat day” that allows for eating whatever is desired, however I would suggest something far more conservative. I incorporate a high calorie day, which corresponds with high intensity training. My poison is 85% dark chocolate and almond butter.
As indicated earlier, insulin is one of the most important benefactors of any IF regimen. Many consider the early morning hours to be the best time to eat carbohydrates due to insulin sensitivity. However, it turns out that insulin sensitivity is only greater due to fasting over night, not because of the morning. Therefore, if you are fasting for 16 hours or more (rather than 8-10 for sleeping) you will see better insulin sensitivity.
More importantly for muscle growth, if you want to take advantage of carbohydrates, it’s best to utilize them later at night. Increased carb intake at night promotes higher growth hormone (GH) production, which will impact muscle repair.
You’re One Hack Away
Intermittent fasting may not be for everyone, but those who test it and overcome a brief period of change usually find that it is an incredibly effective method to improve your life. Busy entrepreneurs, doctors, and anyone else can appreciate a schedule with fewer meals that can improve health and memory. Even aesthetically minded individuals can find common ground with the body composition benefits of IF protocols. Using the information provided above and the evidence to back it up, try for yourself!
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