Intermittent Fasting

Intermittent Fasting has become increasingly popular in recent years for many different reasons. In this guide, you’ll learn everything important you need to know about Intermittent Fasting and how you can practically integrate it into your everyday life. Have fun reading!

What is Intermittent Fasting?

Intermittent Fasting is a form of nutrition in which no food is consumed for a fixed period of time. During the fast, only liquids such as water, unsweetened tea or black coffee are consumed.

Origin of Intermittent Fasting

Fasting, i.e. not taking in food for a set period of time, is a natural way of eating that is very familiar to the body and has been probably since we humans have existed. Before agriculture came into existence and we had a refrigerator at home, food was not so readily and quickly available. A hot meal used to usually involve a time-consuming hunt and therefore tended to be eaten later in the day. Until then, people could only eat light things that could be picked, such as berry fruits.

Fasting was also practiced for religious reasons and still is today. Fasting is practiced in Christianity (Ash Wednesday to Easter), as well as in Islam (Ramadan) and Judaism (e.g. Yom Kippur).

So, after being a natural process in the past and still practiced for religious reasons, fasting made its way into the fitness and health world in 2012 through the television documentary “Eat Fast, Live Longer” and the book “The Fast Diet” by BBC journalist Dr. Michael Mosley. The trend was reinforced by books such as “The 5:2 Diet” by journalist Kate Harrison and “The Obesity Code” by Dr. Jason Fung.

Forms of Intermittent Fasting

16/8 Method

The 16/8 Method, also called the Leangains Protocol, involves fasting for 16 hours each day followed by an 8-hour window of food intake.


In the Eat-Stop-Eat, fasting is done for 1-2 days per week for 24 hours.

5:2 Diet

The 5:2 Diet, also called the Fast Diet, involves eating very few calories 2 days per week and eating normally on the other 5 days.

Alternate-Day Fasting

Alternate-Day Fasting involves fasting every other day. On this day, either no calories or very few calories are taken in.

Warrior Diet

In the Warrior Diet, you eat only small amounts of vegetables, fruits and easily digestible protein during the day, followed by a large meal in the evening.

As you can see there are several methods of how to implement Intermittent Fasting. The methods listed are the most popular and widely used. There is nothing wrong with adjusting the time slots and, for example, fasting for 14 hours and eating for 10 hours or fasting for 20 hours and eating for 4 hours. What is most suitable here also depends on the reason you are doing Intermittent Fasting and what your goal is, e.g. muscle gain or fat loss. First and foremost, you should listen to the signals of your body and can see it as a chance to get to know your body better.

Advantages of Intermittent Fasting

1. Easy implementation

Compared to several small meals a day, which are often not really filling and require more time, or diets that eliminate or greatly reduce certain foods or fats/carbohydrates, Intermittent Fasting is very easy and flexible to implement. Intermittent Fasting allows losing weight with relatively large and filling meals.

2. Time saving

Not only can small meals be less filling during weight loss, they are also more time consuming at the end of the day. Cooking, washing up and generally thinking about what you eat takes longer with many small meals than with a few large ones. Thus, Intermittent Fasting can simplify everyday life and save time.

3. Improved concentration and performance

During fasting, the digestive tract is not busy processing food. Accordingly, less blood circulates in this region, but more blood circulates in the brain. At first, during the transition to Intermittent Fasting, it may not be the case, but once the body gets used to the new diet, many people report increased concentration and performance during the period of fasting. From an evolutionary perspective, this makes sense: having eaten little to no food used to mean that there was still a hunt ahead for which you needed to be mentally and physically activated.

4. Improved skin appearance

Fasting inhibits the production of the growth hormone IGF-1 in the liver. Through constant food intake, this is produced in excess and can thus lead to skin blemishes, such as acne. Fasting, ideally combined with adequate hydration in the form of water, cleanses, detoxifies and improves the appearance of skin all over the body.

5. Improved blood pressure and insulin levels.

The Elizabeth Sutton group of researchers from the University of Alabama at Birmingham (USA) conducted a study to investigate the health effects of Intermittent Fasting. It is worth mentioning that they made sure that the participants did not lose weight during the study in order to rule out the possibility that the health changes were not due to weight loss. The five-week Intermittent Fasting using the 16/8 Method resulted in a significant reduction in blood pressure levels and an improvement in insulin metabolism.

Intermittent Fasting practical example

Since Intermittent Fasting is of interest to many people primarily for losing body fat, the following is an example day for fat loss, fasting for 16 hours and eating for 8 hours.

8:00 – 16:00

Drink water, coffee, tea


Snack, such as 1-2 fruits, to satisfy the big appetite and hunger.


First big meal, filling source of protein, such as chicken breast or fish with a large serving of vegetables, such as a salad


Second large meal, high carbohydrate, such as pasta or rice with a protein source and vegetables.


This is a good time for a snack, such as yogurt or cottage cheese with fruit. Ending the day with a light meal will contribute to restful, quality sleep, which is just as important as diet and exercise.

0:00 – 8:00


Intermittent Fasting Tips

1. Drink a lot of water

Drinking plenty of water is healthy and important, this is common knowledge. It is even more important to drink a lot of water during fasting. When losing weight, it will help you regulate food cravings in the first place. It is also important to know that appetite and hunger pangs may be falsely caused by dehydration. Drinking enough water will help you master fasting with ease.

It also has other health benefits because the organs can regenerate during fasting. Drinking enough water will help this process, allowing the body to cleanse and detoxify itself naturally.

2. Drink black coffee

Together with water, black coffee works very well to regulate appetite during fasting. The effectiveness is even higher if you drink it only during the period of fasting, so the body remains sensitive to the caffeine. Drinking only water for the first 1-3 hours after getting up and then drinking the first cup of coffee can also help to realize the full potential of black coffee.

3. Break fast with fruits

After a few hours of fasting, you get an appetite and become hungry. To avoid eating too much in the first meal, you can first eat 1-2 fruits, such as apples or bananas, to satisfy the first big appetite. Often, this already satiates very well and effectively intercepts the ravenous appetite, so that you can enjoy your first meal with a clear head, or even extend the time window of fasting by another 1-2 hours without any problems until you have your first meal.

4. Short and intense workouts

Burn calories, burn fat, this is obvious to most. But burning more calories will not necessarily burn more fat, because the energy expenditure also creates a natural body reaction: we get hungry and appetite. Exercise and physical activity is important, but beyond a certain point it no longer provides benefit for the effort, at least in terms of fat burning. Therefore, when doing Intermittent Fasting for weight loss, it makes sense to do short and intense workouts. You can do an intense and effective strength training within 60 minutes. If you want to do cardio, a 15-30 minute HIIT workout is better than 1-2 hour jogging for appetite regulation. Walking and trails are also good because we are moving and burning calories, but we are not exerting ourselves as much as longer cardio sessions, and consequently appetite does not increase as much.

5. Big meal after training

After an intense training session, especially heavy weight training, the body needs important nutrients such as protein, carbohydrates but also healthy fats. Therefore, try to place your training ideally before a large meal during the day, so that your body is optimally supplied. For example, if you train in the morning and fast for a few hours after training, it makes sense to supplement your diet with BCAA/EAA.

6. Make the time window of the fasting flexible

As mentioned earlier in the article, there are different forms of Intermittent Fasting with different time windows of fasting. No matter which model you choose, these should only serve as a framework and not a rule. Don’t drive yourself crazy trying to frantically adhere to the time window to the minute. This can possibly do more harm than good. Every person is different, and so are our days. First and foremost, listen to your body’s signals and fast for as long as it feels and works best for you.

7. Commandment instead of prohibition

As with many things, the attitude with which you approach it is crucial to your success with Intermittent Fasting. So try not to focus on not eating while fasting, but on allowing the body and mind to recover and regenerate from food intake. Intermittent Fasting is a great experience both physically and mentally if you get into it and let your body and nature work for you. If you do it right, you will realize how grateful you are for the meals every day when you have consciously gone without for a few hours beforehand.

More questions about Intermittent Fasting

Can you build muscles with Intermittent Fasting?

Yes, you can build muscle with Intermittent Fasting. The prerequisite is a calorie surplus, which means that you eat more calories than you consume. If you find it difficult to eat the amount in 8 hours, you can consider increasing the time window during muscle building.

Can you lose weight with Intermittent Fasting and eat as much as you want?

No, Intermittent Fasting alone does not reduce fat. The decisive factor whether and how much you lose weight is always the calorie intake. This should also be lower than your calorie consumption during Intermittent Fasting. Intermittent Fasting alone does not reduce fat, but it helps to maintain a low calorie intake.

For whom is Intermittent Fasting not suitable?

If you are severely underweight, suffer from eating disorders or regularly take medication and want to do Intermittent Fasting, you should consult your doctor beforehand.

If there are no health concerns in your case, it is recommended to keep the time window of fasting small for the time being and to approach it slowly. For example, you can start by skipping breakfast and see how your body reacts before fasting for a longer period of time, such as 16 hours. If you skip breakfast, you have often already fasted for 8-12 hours, since you have usually not taken in any food during the night.

Can women do Intermittent Fasting?

Intermittent Fasting is suitable for both men and women. Many processes in the body are similar in women as in men. The main difference is usually at the hormonal level. Thus, for you as a woman, it may be appropriate to make the period of fasting shorter and the period of food intake longer.

Women should pay attention to their periods during Intermittent Fasting. If this is not the case, it is not advisable to follow this diet. If you still want to do Intermittent Fasting, you should consult your doctor.

In addition, Intermittent Fasting is not recommended for women who are pregnant or breastfeeding, as they are not only taking care of themselves, but also their child.

What is the difference between Intermittent Fasting and therapeutic fasting?

The main difference between Intermittent Fasting and Therapeutic Fasting is that Therapeutic Fasting is done over a fixed period of time (usually as a cure), whereas Intermittent Fasting is integrated into everyday life and can therefore be practiced over a long period of time, and can become an integral part of one’s lifestyle far beyond a specific nutritional goal. Therefore, one can classify therapeutic fasting as a therapy or diet and Intermittent Fasting as a form of nutrition or lifestyle.

When should you practice Intermittent Fasting?

There is no set rule here. You can train on an empty stomach as well as after a meal. What is more suitable for you depends on your daily structure and on the other hand which goal you are pursuing (e.g. muscle building or fat loss) and when you feel most efficient. For one person this can be in the morning, for another in the evening. What you should keep in mind when planning is that the body needs important nutrients like protein and carbohydrates after a training session. Therefore, if you want to train on an empty stomach, it is a good idea to schedule the training session just before the first meal.

Final words

Intermittent Fasting is a very simple and effective diet that you can integrate into your daily routine for the long term. Besides the most common benefit for losing weight, Intermittent Fasting has many other health benefits and aspects that make life easier. I personally, am a big fan of Intermittent Fasting and have been doing it for many years. People I have worked with have also had good results and positive experiences with this diet.

Have you tried Intermittent Fasting or is it already a part of your daily routine? Feel free to share your experiences with me in the comments, I’m happy to exchange ideas with you. If you have any questions about Intermittent Fasting, feel free to ask me there, I’ll be happy to help you!

Leave a Comment