So you are here because you are interested in intermittent fasting 16/8 or with other words fasting for 16 hours per day, you either want to lose weight or improve your overall health. You probably heard a lot of things about this or you just came here because you heard about this for the first time and you want to find out what intermittent fasting actually is. This will be an in depth article that will try to explain what intermittent fasting is, what types exist, how to implement it in your daily routine, what are the benefits of doing it and point out some of best practices for an easy start. The knowledge shared in this article is based on my readings and personal experiences implementing it in my life.
What is intermittent fasting.
Intermittent fasting in a nutshell is basically just a limitation on when you eat and when you don’t consume any calories. It is not a diet, it’s more a pattern of eating. You can still eat anything you want as long you do it in the allowed time frame. Sounds great right. However we still encourage you to eat healthy unprocessed and nutritionally dense food. There are different types of intermittent fasting, some leave out just the breakfast and others make you fast for more than 24 hours on a time. It depends what your goals are, how fast you want to reach them and what kind of schedule you have currently in your live. It is easier to skip the breakfast If you have a regular job and it is easier not to eat anything if you are traveling a lot. It all depends on many factors and I will try to explain all possibilities so you will be able to make the best choice for yourself.
Scientist have been exploring short-term and longterm benefits caloric restriction by skipping meals since the early 1930s and discovered that it helped the mice to live longer when they significantly reduced calories. More recent studies confirmed this results on monkeys, roundworms and fruit flies. It has been shown by studies, that a decrease of 30 to 40 percent in calories extends the lifespan by as much as one third. There are also many other benefits of reducing calories such as reducing the risk of many common diseases, increase the body’s responsiveness to insulin, which regulates blood sugar and helps with food cravings and makes it easier for you to control your appetite.
The truth is that humans have been fasting for thousands of years.
The major factor with this method is, that your body is genetically adapted to fast for longer periods and is not well equipped to being constantly bombarded with food each and every day. Our ancestors didn’t had the luxury of eating 3 steady meals each day with some snacks in between. The fact is that most time in our existence we didn’t eat for longer periods of time and then had a big meal and that is why our bodies are so well adapted to that kind of food regime. Our ancestors hunted for food for days, enduring great physical effort without having any food and after the successful kill they eaten like kings for days.
Intermittent fasting helps you lose weight
The longer the window when you don’t consume calories the faster you lose weight. Normal diets that just restrict your caloric intake and decrease your body’s metabolic rate as a result which puts you in a vicious circle of eating less and less and you don’t lose just fat but also muscle tissue which in turn slows your metabolic rate even further. Studies have shown that when doing intermittent fasting it actually increases your body’s metabolic rate, increases growth hormone production and you lose mostly body fat as it helps retain muscle tissue in contrast to other diets. Your body adapts to this by getting more efficient in using fat as energy source and that is exactly what you want to achieve. It does not even limit or encourage you to eat only certain foods you can eat whatever you want and even if you eat the same amount of food in this shorter window it will still have some benefits for your fat loss process.
The science behind intermittent fasting is, that your body can store for about 12h of available glucose in your body, after that period you need to fill up the carbs so to say. When doing intermittent fasting we are trying to avoid eating any calories for at least 14-16h, and eat only in the remaining window of the day, so we have a window of about 4 hours where your body doesn’t have available glucose to use and it’s forced to go into fat burning mode, which triggers many processes and is what we want to achieve, so it is that time after around 12 hours that is actually making that difference and that is why you should go fasting for at least 14 hours for women and 16 hours for men. When your body is in fasting state all sorts of good processes start to happen in your organism.
- Your insulin and leptin sensitivity increases
- Normalising ghrelin levels, ghrelin is also known as “the hunger hormone”
- Growth hormone (HGH) levels increase, which plays an important part in health, fitness and slowing the aging process.
- Body releases more cholesterol, allowing it to utilize fat as a source of fuel, instead of glucose. This decreases the number of fat cells in the body
- It lowers your bad cholesterol and increases good cholesterol levels
You can achieve all of this benefits simply just by skipping breakfast and maybe delay your lunch. From my experience this is not hard to do especially once you get used to this eating pattern. I also noticed it is really practical as you need less time to get to your work, so you can start earlier and do more. If you wish to push it even further you can just expand the time frame when you are not eating to let say 18h so you only eat in the remaining 6h.
What are the benefits of intermittent fasting
Intermittent fasting offers many benefits, the most obvious one is of course for losing that excess weight. While losing stubborn belly fat great on it’s own intermittent fasting offers many other health benefits, such as prolonging your life and increased physical performance.
Intermittent fasting makes you live longer
As we have already mentioned, restricting calories is proven to prolong your life. When you are starving, your body functions differently and is disposing of old and damaged cells more efficiently that it does on a full stomach. The main thing is that it is kind of hard to starve yourself just to add some time to your lifespan even if everyone would like to live longer people are not likely to do that. The good news is that intermittent fasting provides some of the same benefits that calorie restriction does without you actually starving. You can reap the same benefits for the price of skipping a meal.
Studies: 1, 2
Intermittent fasting greatly increases your own body’s growth hormone (HGH) production
Growth hormone is an anabolic hormone and it is responsible for cell growth and regeneration. It increases muscle mass and bone density and it plays a major role in maintaining health of all body tissues, including brain and other vital organs. HGH also helps improve your sleeping patterns and betters REM-stage sleep. It also boosts your overall energy levels. It is the so called youth hormone as it slows down the effects of ageing.
A recent study on intermittent found out that fasting triggered a dramatic rise in HGH 1,300 percent in women, and an unbelievable 2,000 percent in men! The only other thing that can come close in terms of dramatically boosting HGH levels is HIIT or high intensity interval training.
Intermittent fasting can reduce the risk of cancer
So the statement above is a bit bold so take it with some reservation. There have not been performed many studies about this subject, but the ones that have been are promising. The results however are not dramatic but are showing some potential. Studies performed on animals show a decrease in cancers in the range from 25% to 40 % which means it is not a cure but it still substantial.
Main reasons why intermittent fasting is good for cancer prevention:
- Being overweight increases the risk of different forms of cancer and losing that excess weight contributes to prevention.
- It decreases the glucose levels in your blood which is the main energy fuel for cancer cells.
- Fasting also decreases the amount of insulin-like growth factor 1 (IGF-1) which is also linked with increased cancer risk.
- Fasting switches your body from growth mode into repair mode and disposes more efficiently of damaged cells, this particularly affects the cells that have the potential to turn into cancerous cells.
- Intermittent fasting enhances the ability of nerve cells to repair DNA.
Intermittent fasting is practical
To be honest, being able to skip your breakfast is actually really practical and makes your day easier. I always used to eat breakfast before going to work, and to be honest it took me about 30 min every day to make and eat my breakfast. If you take this 30 min and do some exercise like HIIT every second day you will do yourself and your body a great favour. On the other hand if your job allows it you can get to your job 30 min earlier and and also finish earlier giving you more free time to do thing you love in your life.
Intermittent fasting is good for your brain
Human and nonhuman animal studies have shown that intermittent energy restriction increases synaptic plasticity(a biological marker of learning and memory). It enhances memory performance and leads to the growth of new neurons, decreases risk for all neurodegenerative diseases like Parkinson’s and Alzheimer’s disease, promotes recovery after a stroke or brain injury and it has also been shown to play a big therapeutic role in mood disorders like depression and anxiety. During fasting, your body increases activity and growth of neurons which can help you think faster and more creative and it improves your memory. Your brain also functions exceptionally well on ketones, which are produced by your body when it runs out of glucose. I have experienced a boost in cognitive functions as effect of intermittent fasting but it is the most noticeable at the beginning.
Intermittent fasting lowers blood pressure and resting heart rate
Losing weight in itself lowers blood pressure, but there are also other benefits that contribute to this. Lower body fat helps alleviate extra workload put on the kidneys which as a result lowers blood pressure. Intermittent fasting also increases HGH production which results in much better cardiac function.
Intermittent fasting normalizes your blood sugar
Fasting helps normalizing your body’s insulin and leptin sensitivity, which is key for optimal overall health as insulin resistance is the main contributing factor to most of today’s chronic disease, from diabetes to heart disease and even cancer,
Different methods of intermittent fasting
Fast 16 hours eat 8 hours
A 16 hour fast a day is probably the most common method of intermittent fasting. Some may split it up to 14 hours for women and 16 hours for man but I don’t think it is necessary. It is very simple, you simply skip the breakfast and have lunch as late as possible or you don’t eat anything after lunch until the breakfast next day. One can have coffee or tea before lunch, but nothing that has any calories so no sugar or milk in your drink. To eat no calories is actually really crucial in this, because as soon your body gets any sugar it will raise your blood sugar and make you even more hungry, so it will be more difficult to make it until lunch without any food.
This is probably the easiest method of intermittent fasting out there as it is really simple and you can slowly progress to it. To give you an example: If you finished your dinner at 21h (we count time from the time you have finished your last meal until you started eating your next meal) the day before and you have your breakfast at 10h in the morning, you have already done a 13 hour fast. This is really not hard to do and a lot of people are actually doing it already. Now you can just push back your breakfast or skip it until your lunch. It is really simple if you do it slowly and you don’t need that much willpower to do it. Once you reached 16 hours of fasting you can work it up even further up until 18 or even 20 hours. But you really don’t need to push it that high as even 16 hours of fasting each day is plenty and you will rip all the benefits of intermittent fasting.
I personally like to skip the breakfast and have my lunch as late as possible. Sometimes I have only 14 hours of fasting and sometimes I have 18 or even more hours of fasting. It doesn’t have to be the same each day as long as you average it around 16 hours or more. And on the weekends I usually have one normal day and I eat when I feel like it, but the thing is that once you get used not eating let say in the morning you really don’t feel hungry and I usually have a much later and smaller breakfast than I normally had.
Fast for 24 hours once or twice a week
So this is a little different method than the one we described earlier, it is still pretty straight forward and people have been doing 1 day fastings in various religions or for body cleansing / detoxification for ages. The principle is simple you just fast for at least 24 hours or one day which is a bit more. If you fast for 24h you can have dinner in the evening and finish eating let’s say at 8pm and than you don’t eat anything until 8pm the next day, so you stopped eating at 8pm one day and started eating at 8pm the day after. The entire day method is a little longer, so you don’t eat anything the entire day, so your next meal would be the breakfast 2 days after your dinner. For me personally this method is harder to endure and I don’t practice it that often.
The benefits of this method are that you push your body even further and it has some great detox advantages as it gives your body even more time to cleans the toxins out of your system.
The cons are pretty obvious, some people have difficulties to endure 24h or more without any calories.
One large meal per day 20h fast (advanced)
This is an advanced version of the first method we described, and it differs only in fact that you basically eat only one large meal per day. You don’t actually have to consume all of your daily food in one go, but the window in which you are eating should be kept really small somewhere between 2 and 4 hours. This eating pattern was practiced by roman soldiers back in the day and was probably a pretty standard way of eating in the old days. Roman soldiers would walk for entire day and have a big dinner in the evening. They had to endure great physical efforts and were in top shape. This type of intermittent fasting is also called the warrior method.
The pros for this method are that you push your body even further into body fat burning mode and it is really simple for practical reasons as you have to worry only about the dinner each day.
The cons are that some people might find it hard to endure this, so it is not advisable for this method to be the starting method for your first intermittent fasting. You can easily slowly progress to this method from the 16h fasting method and you can control what kind level of fasting is still comfortable for you.
Interval fasting: 1 day 16h fast and limit calories in the remaining window, next day is normal.
This is a up and down approche, you cycle your calorie intake from one day to another. First day you make a 16h fast and you also restrict the amount of calories you eat on that day to about 500-800 calories that day. Next day is business as usual and you eat as much as you normally eat, you should not eat much more than you used to before the fasting. This method is a mix of our standard skip your breakfast method and alternating fasting day, it is not that demanding but you need to count your calories for the fasting days which is somewhat annoying to some people and is not that popular among people.
The pros are that you have to fast only every second day and can eat normally on the off days.
The cons are, that it is not that effective, you need to count your calories and you don’t operate in a daily pattern.
Alternating fasting day: You eat one day and fast the next
This is a more advanced version of previously discussed interval fasting method. This is a fairly advanced approach and a difficult to commit for a longer time. This style is not popular among people and I haven’t tried it myself, but it seem to be very popular among science researchers as most studies are performed with this method.
In practice this method makes me wonder if it is sustainable in the long run as it restricts the food intake too much and you could suffer some sort of nutrient deficiency because of that. I also think that it is hard to stay with this as you do not create daily repeatable habits that you can get used to but it is rather going from one extreme to another.
On the other hand, this method is probably one of the more effective methods of intermittent fasting and is probably good if you already have experience in intermittent fasting and would like to mix things up and speed up your fat loss progress.
Taking it a step further
So normally when you do intermittent fasting you don’t need to care what type of food you are eating, but if you wish to take it to the next step, you can also consider eating cleaner food in the eating time frame. You should take care of your body and eat nutrient dense food so you get all the nutrients your body needs for optimal performance.
What I would recommend is to eliminate all processed foods, such as white flour, white sugar anything bought pre made and in a grocery store. Try to increase the consumption of healthy fats and limit amount of simple carbs. Try to eat grass fed meat, free range eggs, and lot of greens. Put some effort in and prepare most of your food yourself, don’t eat out every day, restaurants with high quality and healthy food are rare and expensive. You will be surprised what a change can intermittent fasting and good healthy nutritional food have on your body.
My tips for starting your first Fast
Get familiar with all possible types of fasting first, make sure you are healthy consult your doctor and know in what you are getting into. I would advise you to go slowly and make progress by steps, this will also make it possible to make the most out of it as intermittent fasting is most effective when your body is adapting to new fasting period. If you start slowly and prolong the fasting window each week for one hour you won’t even notice it and you will still make good progress.
Risks and side effects of intermittent fasting
You will be hungry, but that should be only temporary and your body will adjust to your new eating pattern and make it much less difficult for you.
While your body is adapting to this new eating regime you might feel weak, lightheaded and your energy levels will be fluctuating. This symptoms should also be just temporary, about 2 to 6 weeks, while your body adapts and improves the ability of using fat for energy needs.
If you have any medical conditions you should consult your doctor and monitor your health in case you choose to do this type of fasting.
This is even more important if you have any of this:
- Problems with blood sugar regulation.
- Low blood pressure.
- Are underweight.
- History of eating disorders.
- Are a female who is trying to conceive.
- Are a female with a history of amenorrhea.
- Are pregnant or breastfeeding.
- Take medications.
What to eat – food list
Even dough there are no restrictions regarding what you can or cannot eat during intermittent fasting, we recommend you eat a healthy variety of highly nutritional foods. Try to avoid foods with high calories and low nutritional value. Load your body with the nutrients it’s been missing with just a few bites of these foods.
- Brussels Sprouts
- Turnip Greens
- Sunflower Seeds
- Black Beans
- Sweet Potatoes
- Green Peas
- Collard Greens
- Bok Choy
While you should eat a healthy amount of foods that are described above you should also avoid sugar, drinks filed with sugar like coca cola, simple carbs like pasta and white bread, and all fried foods as vegetable oils become carcinogen on high temperatures and are therefore highly toxic and should be avoided by any means.