everything about intermittent fasting

Breakfast like a king, lunch like a prince and dine like a pauper” – is that still true or just an old outdated saying?

Over the last few years the health & fitness industry has been telling us how important it is to have a big & satisfying meal to get you started for the day.


The diet world is a big one, with new theories arriving almost every season. Leaving us confused and insecure.

Let’s bring light into the darkness and delve into the word of diets:



What is intermittent fasting?

Why fast?

Fasting benefits

Why & how it works

What happens during a fast?

When to eat

What to eat

Most common methods of intermittent fasting

What to bear in mind – mistakes to avoid

Why give it a try?


Final words


What is intermittent fasting?

Fasting is a term describing a period of time when you choose to not consume any calories in a controlled practice, which means a state of not-eating.

Fasting in this way has many health benefits and has been used throughout history.

There are many ways of approaching a fast, intermittent fasting is one method.

Intermittent means “occurring at irregular intervals; not continuous or steady“.

The most important element of intermittent fasting is when you eat, and when you don’t. You will consume your daily calories only during a certain time window throughout the day. For the remaining hours you will fast. This may sound shocking at first, but let me take that away by telling you: you already do that every day. For example, if you eat dinner at 8pm and have breakfast the next morning at 7am, you are already doing an 11 hour fast every day.


It is important to understand that intermittent fasting should not be seen as another diet, but much more like a way of living & eating – as a tool helping you achieve your health goals.

Yet it is not a magical cure-all that guarantees weight loss. Our weight still depends on many factors, such as calories in vs calories out. It is simply a tool with a variety of great benefits, which will be a support on your journey to your goals – not a promise.

Bearing that in mind, let’s jump into the benefits:


Why fast?

In todays world there is an oversupply on food – at every hour, on every corner, we can have whatever we want. Food choices at our fingertips with no limits is given as granted 24/7.

But it hasn’t always been that way – our ancestors occasionally had to go days without food. Even though they developped ways to preserve and save foods, they still had periods with little or no food at all. Intermittent fasting was a common practice.

Our bodies are not designed to work (absorb, digest, eliminate) constantly. By including a fast, we give our bodies a break – some time to restore, recover and rest.


Fasting benefits

  • weight loss (switching from burning glucose to stored body fat for energy)
  • waste gets cleared from cells / detoxification -> rejuvenation + preventing diseases such as cancer, Alzheimer…
  • improves sleep
  • balances blood sugar levels -> protects against type 2 diabetes
  • reduces blood pressure, heart rate & bad chortisol
  • improves cardiovascular functions
  • increases energy
  • improves metabolism
  • reduces inflammation (fasting is a way of detoxification)-> improves allergies
  • improves digestion by giving your digesting system a break -> enables you to extract maximum nutrition from your meals
  • improves brain function by promoting new brain cell growth
  • boosts immunity by eliminating toxins + increasing amount of healthy bacteria in your gut
  • heightened mental clarity, memory, focus and concentration
  • studies show it can even reverse type two diabetes by improving insulin sensitivity
  • raises levels of HGH (human growth hormone) -> increasing muscle mass, strengthening bones, better sleep, higher energy level
  • improves mental health by having positive effects on mood, alertness and creating a sense of peacefulness
  • reduces the risk of cancer and heart diseases (still a controversial approach as there are not enough studies to proof this yet). Cancer cells are glucose-dependent, through intermittent fasting less glucose is absorbed
  • heals your body (cell regeneration & repair) – no sickness can live if you don’t feed it!
  • enhances appetite control
  • reduces cravings: alcohol, food, nicotine – food cravings are reduced by using fat stores for energy -> reduces dependance on high carb foods for fuel + won’t turn to food during a fast when emotionally hungry
  • normalizes hunger hormone
  • promotes mindful eating & an appreciation of real whole foods


Why & how it works

There are 2 phases – the feeding and the fasting phase.

After eating a meal, our bodies need a few hours to absorb, digest and utilize the energy. Given energy in form of food can be called “easy energy” as it moves into the blood stream and can be used for energy immediately.

Throughout a fasting period there is no “easy energy” available and therefore more likely to take its energy from stored fat.

By incorporating intermittent fasting, our body learns how to use energy from food more efficiently.


  • during later stages of short term fasting, our body increases hormonal levels regulating appetite and body fat
  • impacts how your body repairs its cells
  • after 12 hours of fasting, growth hormone works at its best – because insulin level is very low
  • after 24h of fasting, certain cells in our guts start to regenerate


What happens during a fast?

4-8 hours

  • food left stomach
  • blood sugars fall
  • no more insulin is produced

8-12 hours

  • your last meal eaten is still in circulation in your body
  • it hasn’t reached the state of fat burning yet

12 hours

  • food consumed has been burned -> your body enters the “fasting state”
  • digestive system finally can rest
  • you’re about to enter the fat burning zone
  • body starts its healing process
  • muscle growth hormonal (HGH) levels are raising

14 hours

  • HGH increases a lot more
  • stored fat is now used for energy

16 hours

  • you’re in the fastest fat burning zone
  • as your muscle growth hormons are even higher, it’s a great time to workout

18 hours – 20 hours

  • body is in fat burning mode
  • HGH are skyrocking

24 hours

  • you have reached the peak of fat burning
  • ketones are released into blood stream


When To Eat

  • devide your day into two parts: “eating” and “non-eating” time frames – it’s all about meal timing
  • 12 hours is minimum (optimal for beginners). The benefits only start at 12 hours
  • between 14 and 16 hours are the most common fasting periods
  • 20 hours is considered extreme
  • it’s personal. experiment around with what works best for you!
  • make it fit your daily schedule – allow yourself to be flexible and shift the feeding / fasting windows accordingly


What To Eat

Intermittent fasting doesn’t require specific foods or diet to work. This makes it very flexible and allows it to be combined with other diet philosophies like low carb, vegan, vegetarian, and simply eating healthy.

  • Important!: Don’t overcompensate or binge in between fasts


Most common methods of intermittent fasting

Your diet is a very personal thing. It is important to do what makes you feel your best. Feel free to constantly try around as your needs might be shifting. We are not static beings, and neither is our way of living & eating. No one but you, knows what works for you!


12 hours fast

This approach is reccomended for beginners. The fasting benefits start at 12 hours. Therefore if you want to reap the fasting benefits, 12 hours is the minimum. But as with everything, start slow and walk into the game step by step.



I find this one to be most efficient and easiest to incorporate into a daily routine.

  • daily fast of 16 hours
  • eat for 8 hours

Allow yourself to be flexible with the phases of your feeding & fasting windows:

If you ate dinner at 8pm, you will eat your next meal at noon the next day.

If having breakfast makes you feel better, eat your last meal at 4pm and break the fast at 8am the following day.



  • daily fast of 20 hours


Alternate Day Fasting

  • one day fast, one day feed



  • fasting for 24 hours, 1 to 2 days a week


Version 1) The 6:1 Fast

  • fast 1 day per week


Version 2) The 5:2 Fast

  • eating normally for 5 days of the week
  • fast for 2 days per week, or only consume small meals of 500 to 600 calories for 2 “fasting” days of the week

Feel free to do and try whatever you want, but I personally do no recommend this method!! This is very close to a “normal” diet, suggesting calorie restriction, which in my eyes is never a good idea.


The Warrior Diet

  • modified version: eat for 4 hours, fast for 20
  • original version: eat raw veggies & fruits during the day, and one large well-balanced meal at night

Essentially, this type of fast allows you one big meal in the evening and the rest of the day is spent without eating. However, you are allowed small portions of raw fruit and vegetables, as well as protein throughout the day.


What to bear in mind – mistakes to avoid

Before jumping into it head over heals, it makes sense to become clear on how you want to incorporate this into your daily life. I created a post about the 8 most common mistakes in order for you to avoid them.

While intermitted fasting is a great tool with many benefits, it might not be an approach for everyone. If you suffer from diabetes, or other severe health issues, please talk to your doctor before making any changes to your diet & lifestyle.


Why give it a try?

  • it’s simple & easy
  • it works
  • it can be personalized to fit your daily life
  • it’s not a diet – no bans on certain foods
  • it’s convenient
  • it helps avoid overeating
  • see the lists of benefits above



during fasting time, no cals

don’t consume any calories during your fasting periods – stick to plain water and black coffee in order to remain in a state of fast

avoid overeating

avoid overeating or bingeing during your feeding phase

eat enough

make sure you eat enough – no matter if you eat 6 smaller meals or 2-3 bigger meals. It is important you get all the nutrients through a well balanced diet

choose quality

not only is it important to eat the right amount, but also to pay attention to the quality of your food. Choose a high-quality & unprocessed diet full of Whole Foods fueling you with the essential nutrients

stay hydrated

ensure that you drink enough water throughout the day. Listen to the thirst signals of your body. I like to always walk around with a big bottle of water, so I always have some water at hand

needs to fit your lifestyle

make it fit your daily schedule – allow yourself to be flexible and shift the feeding / fasting windows accordingly


Final words

Intermittent fasting does not necessarily mean weight loss. It is very much possible to maintain your weight, gain body fat or add on muscles.

Do it for the right reasons! Don’t do because others are doing it. Have your own good reasons and the right motivation to do it.

Make it individual. Don’t just do what others are doing. Always listen within and do what feels good and right for you.


If you have doubts, questions or experiences you would like to share, please do not hesitate to reach out to me. You can contact me via the contact form or send me a dm on Instagram @sarahgluschke.


Begin by asking yourself following questions:

  • What method do I want to try?
  • What is my main motivation?
  • Who can I do this with?
  • What will be my fasting hours / my feeding hours?
  • How can I best incorporate this into my daily life?


As always, this is a journey. Enjoy it!



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