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Is Intermittent Fasting Unhealthy? Everything You Need to Know About

Is Intermittent Fasting Unhealthy? Everything You Need to Know About

What is Intermittent Fasting? Is Intermittent Fasting Unhealthy? Should you try it? These are the questions I can find in various different forums from people all over the world. This type of diet is getting more and more popular among people, in fact, this is one of the most popular health and fitness trends, but many still don’t know what intermittent fasting actually is and if is it safe and good for us.

I will answer the most common questions about intermittent fasting and give you an idea of what this diet is all about.


What is intermittent fasting?What is intermittent fasting

This is a type of diet which involves alternating cycles of fasting and eating. This diet is very different from other diets, because it doesn’t say what food you should eat, but it says when you should eat that food. The main goal of intermittent fasting is to split the day into fasting and eating periods by shortening the eating period and extending the fasting period.

Most people in the world do not eat and fast while they are sleeping, which can be somewhere between 6 – 10 hours of fasting. The goal is to extend your fasting period and the best way to do that by not eating at least a few hours before sleep and skipping your breakfast.


Intermittent fasting types

The 16/8 method: This is the most popular method of intermittent fasting. Where you have to fast for 16 hours a day and eat for 8 hours in the middle of the day.


The 18/6 method: this method is a different version of the 16/8 method where you have to fast for 18 hours and eat 6 hours in the middle of the day.


Intermittent fasting types

The 20/4 method: this is the most extreme version of the 16/8 method where you have to fast for 20 hours and eat just 4 hours in the middle of the day.


The 5:2 method: for five days of the week you have to eat normally and following with two days of modified fasting consuming very little amount of calories, somewhere between 500-600 calories a day.


Eat stop eat method: for six days of the week eat normally and one day of the week fast for a full day.


There are more intermittent fasting types, but I’m not going to talk about them, because they are not as popular and I think some of them are too extreme and not worth the risk to try them.


Why intermittent fasting works?

This works, because of the extended starvation period which decreases insulin level and makes our body burns fat to get energy and help to lose weight quicker.

Food makes our insulin levels to spike up, which leads our bodies to store sugar and produce body fat (turn sugar into fat). Eating every three hours as told by many ‘’Gurus’’ increases our insulin level all the time and our body keeps storing those extra calories.

Eating less often is actually better and can help to lose weight and increase metabolism because we don’t spike our insulin level that often gives our body the opportunity to start burning that fat and turning it into energy.

It can also help your digestion system because it has more time to digest food properly and get rid of all waste and toxins before you eat more food. If we are eating every couple of hours our body don’t get this opportunity because our digestion system is always full.


Does intermittent fasting burn muscles?Does intermittent fasting burns muscle

The answer is no. Our bodies are not stupid and it is just a myth that we have to eat every 3 hours to grow muscles. Actually, researches have shown that the human has to fast for more than 48 hours before the body starts burning muscle fibres.

During fasting, the body first breaks down glycogen into glucose for energy. After that, it will breakdown fat to provide energy for our bodies. And just in the last option, it will start to break down muscle fibres to use as energy.

Don’t be afraid to lose your muscles because of intermittent fasting, because it’s very unlikely to happen.


Is intermittent fasting unhealthy?

Is intermittent fasting unhealthy? This is the most important and common question people ask. I couldn’t find any research proving that intermittent fasting is unhealthy, in fact, it has a lot more pros than cons. And I will talk about them later. Read more about intermittent fasting studies.

However, I would not recommend too extreme methods of intermittent fasting, because you still want to give yourself enough time to get all nutrients and calories you need, especially if you are lifting weights and trying to gain muscle mass. I would recommend the most popular method 16/8 where you fast for 16 hours and eat for 8 hours.

I would choose my eating hours from 12 pm until 8 pm, but you can choose any time gap which suits your lifestyle better. And don’t forget that you have to eat good quality food, to supply your body with all the necessary nutrients, vitamins and minerals.


I would not recommend intermittent fasting for people who are:

  • Underweight.
  • Having or ever had eating disorders like anorexia in the past.
  • Pregnant.
  • Breastfeeding.
  • Children under 18.


Intermittent fasting benefits

Intermittent fasting has lots of benefits. Weight loss is the most obvious one and the reason why most people are trying intermittent fasting. Some benefits like weight loss are approved by many types of research done on intermittent fasting. There are many possible benefits which have not been 100 percent approved by research yet, but there is a great possibility of them too.


Some of these possible benefits are:

  • Lower risk of type 2 diabetes.
  • Increased metabolism.
  • Increased growth hormone which is responsible for muscle growth.
  • Improved cholesterol level.
  • Lower risk of Alzheimer.
  • Reduction of inflammation.
  • Increased concentration.


Approved benefits of intermittent fasting:

  • Weight and body fat loss.
  • Lower blood insulin level.
  • Increased fat burning.


Key points

  • This is a diet which involves alternating cycles of fasting and eating.
  • Most popular intermittent fasting type is 16/8 method where you have to fast for 16 hours a day and eat for 8 hours in the middle of the day.
  • This works, because we are extending the starvation period and that decreases insulin level and makes our body burn body fat for energy helping to lose weight.
  • This decreases spikes of insulin level which has a positive impact on our health.
  • No research can prove that intermittent fasting is unhealthy, in fact, it has many positive health benefits.
  • I would not recommend extreme methods of intermittent fasting, you should try the 16/8 method.
  • Eat good quality food, to supply your body with all necessary nutrients, vitamins, and minerals. Not sure what is good quality food you can find out more in my article about the Importance of Balanced Diet. 



Are you curious and want to try intermittent fasting? Yes? I would recommend trying it out and see yourself how you feel and if it is the right thing for you or not. My recommendation is to try out the most common 16/8 method and do not choose too extreme methods which can affect you negatively.


As always, if you ever need a hand or have any questions, feel free to leave them below and I will be more than happy to help you out.

All the best,

Marius Mickevicius

Founder of ihealthylifestyle

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16 thoughts on “Is Intermittent Fasting Unhealthy? Everything You Need to Know About”

  • I practice intermittent fasting and am loving the results. More energy, no more afternoon mental fog after lunch and overall healthier feeling. I’ve come to learn that breakfast is overrated and I have gained valuable time back. Who can argue with results like that. Thanks for pushing something that is good for all of us.

    • Breakfast is definitely overeaten and it is not that important to have breakfast as so many articles says, in fact, it is a lot healthier not to have breakfast, especially when you just woke up. I have tried intermittent fasting 16/8 method and I’m loving it, a lot more energy, better digestion, I can even grow lean muscles quicker and easier. It is definitely worth trying.

  • I have also heard that when one fasts that sick or malformed flesh gets eaten by the body on a cellular level, I am not sure if this is true or not.

    • I heard about that to Bob, but I can’t confirm it’s true because I have never found enough research and proof that it is true, but your body definitely gets rid of toxins during the fasting period.

  • Last year while overseas I stuck to the 16/8 fasting cycle for about 4 months. I felt great. My body seemed to have more energy than when I am eating the normal 8/16 no fasting way. I’m back to my normal hard physical working routine now which means I have a big breakfast at 6:30 am, have lunch and then dinner at about 7:00 pm. However, I feel that I am doing this more out of habit, and to fit into the family routine rather than because I actually need this amount of food. The habit and routine are hard to break, but on the weekends I do manage to skip the breakfast so do consume less and I always feel better for it. Thanks for sharing your pros for fasting. They are inspiring me to break the habit of eating just because it is what we are used to doing.

    • So you have tried and experienced yourself that intermittent fasting really works, I have done it in the past too and know many people who are still doing it and achieving great results and feeling a lot better. Shame that because of my work schedule it is very hard for me to stick with intermittent fasting at the moment, but I do the same as you and try to stick with 16/8 eating schedule at least on weekends and I actually feel great. I think all skeptical people should give it a go and experience it themselves.

  • Fasting is something that has incredible health benefits, including raising testosterone levels, according to some research, which actually indicates that fasting has the potential to INCREASE muscle mass – give that testosterone builds muslce.

  • Hi Mario, Many thanks for your post showing what intermittent fasting is and the various types of fast. Other tips like helping the digestive system to digest food properly and get rid of toxins before more food is taken in, decrease in insulin level that make our body to burn fat and gain energy is very useful info for me. These facts are not so obvious as the losing weight aspect.
    On the Christian spiritual fasting side I’ll say that using the same 16/8 principle and combining it with prayer also has benefits like sharpening your mind to think clearly, and being healed emotional ly and physically.
    I’ll also not advice extreme methods of fasting but when done right intermittent fasting does have physical, emotional and spiritual benefits.

    • Thank you Irene. Many people think that intermittent fasting is just about losing weight and not many know other benefits of intermittent fasting, that’s why I wanted to list all other benefits of it. Of course, if you choose too extreme method it might make more harm than good, everything in life should be in perfect balance if we want to get benefits of it.

  • Very interesting article. It never cross my mind that fasting can be done in so many different variations. In the past, fasting to me is as simple as skipping meals, never have I thought about the 18/6 or 16/8 kind of fasting. Thank you for sharing and your ideas are very relevant and helpful to those who wants to fast.

    • Yes, intermittent fasting has so many variations I haven’t listed them all, but some of them are just too extreme and I didn’t want to share them with people as I think they are unsafe. I think the best and safest option by far is the 16/8 method, which definitely worth trying.

  • Thanks, I really appreciate the rundown of the different types of IF available. I actually recently placed a client on a 16:8 IF schedule in part because it seemed to fit nicely into her normal schedule. She wasn’t much of a morning eater anyway, so it was mostly a matter of adding a few hours on to her fast to hit that 16-hour mark. Good to hear you believe that is a good place to start.

    And if that doesn’t work, I can explore some of those other options!

    • I’m glad you believe in intermittent fasting and you placed your client on the best method to start and I have known many people and have plenty of examples that intermittent fasting really works. It’s great that there are so many different methods of it and every person can find what is the best fit for that person.

  • I also agree with you the best intermittent fasting is 16/8, and it’s the one that I follow. I feel like I don’t overeat during and stick to my meal plans.
    I used to skip meals before thinking that it would eat less during the day but found myself snaking high-fat food more.
    What would you recommend I could eat if I felt peckish but didn’t want to eat high calories and high-fat snacks?

    • Yes, 16/8 is not an extreme method, but still works very well as people tend to eat and snack more than 8 hours per day. You could have some low-calorie snacks as Shrimps, celery, scallops, carrots, blueberries, asparagus, low-fat cottage cheese or greek yogurt, egg whites, broccoli, apple, lean beef, spinach, you can make nice salad mixing some of these low-calorie products. I hope it did help.

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