Intermittent Fasting – Short-term Fasting – IF

1) What is Intermittent Fasting?
Intermittent Fasting is not a conventional diet whereby what one may eat is prescribed but one by which only when one may eat is defined. Thus, one is not obliged to forgo any particular food; the only constraint being to set the duration of the main food-free window. Periods of fast are nothing unusual, we experience them regularly when we sleep and the concept is embedded in many languages e.g. “breakfast” in English is the ‘breaking of the (night) fast’; “déjeuner” in French is the ‘undoing of the fast (jeune)’ and “Frühstück” in German is the ‘early bit’ that ends the short-term (night) fast.


2) How does one introduce Intermittent Fasting in one’s daily life?
Intermittent Fasting is easily incorporated into everyday life since it can be synchronized with differing individual routines; even irregular work or night-shifts can be accommodated. Which form of Intermittent Fasting to practice and where to position meal-times and fasting-breaks within the day can be self-determined and even varied.

The simplest introduction to intermittent fasting occurs (according to many of those who have fasted) after a fasting cure – why?

    1. Because one develops confidence in one’s body’s resilience: the experience of spending a week or more without food without feeling hunger, makes most people realize that skipping a meal does not lead to starvation.
    2. Because the benefits of one’s Fasting Cure can be prolonged.
    3. Because one is motivated to improve one’s nutrition.


Mint leaves isolated over white background
3) Different Forms of Intermittent Fasting
Fasting is not a competition: it’s not like a diet which aims to shed weight quickly. Intermittent Fasting is a fundamental and permanent lifestyle change and thus a constant and lifelong boon for the health of body and mind. The benefits come one step at a time and remain – there is no “yo-yo effect”

There are different forms of Intermittent Fasting but two basic types have established themselves:

Daily Short-term Fasting (16/8, 18/6, 20/4)

  • 16/8 – 16 hours without solid food with a „feeding window“ of 8 hours
  • 18/6 – 18 hours without solid food with a „feeding window“ of 6 hours
  • 20/4 – 20 hours without solid food with a „feeding window“ of 4 hours

Short-term Fasting with whole fasting days or „Interval Fasting“

  • The 5:2 Diet“ (from Dr Krista Varady and Michael Mosely)
    5 days of normal eating and 2 days of fasting – on any two days of the week up to 500 kcal can be consumed per day as solid food and on the other five days normal eating as desired is allowed.
  • The Every Other Day Diet“ (EOD) and „The Alternate Day Fasting” (ADF)
    On one day one eats as one will and on the next day, only 500 kcal are allowed.


4) What should one pay attention to within the fasting window?
During the fasting periods it is important to drink plentifully and to mind that the drinks are free of sugar or artificial sweeteners and be as natural as possible. Water, tea and black coffee are best suited. If a drop of milk needs to be added, well, so be it! Although recent studies show that drinking your coffee black accelerates autophagic processes.

Intermittent Fasting-Drinking Coffee


5) What to do when feeling hungry?
  1. Drink! – Drinking reduces the sensation of hunger.
  2. Hang in there! The feeling of hunger generally subsides within 10 minutes.
  3. Enjoy! Hunger tells you that from this point on, the bulk of the body’s cellular regeneration is taking place.


6) Is it possible to lose weight permanently with Intermittent Fasting?
Yes, you can lose weight permanently with Short-term Fasting. Weight loss occurs slowly compared with conventional dieting but is healthier, easier and above all, permanent. As already stated, Intermittent Fasting is not a diet but a fundamental change in eating habits and therefore there is no subsequent weight gain as is the case with so many diets (“yo-yo effect”). Those who fast regularly, learn to distinguish between hunger and appetite, enjoy their meals more than before and eat “conscientiously”. They report hankering after healthy foods at the end of their fasting and enjoy their meals more than before. Thus daily Intermittent Fasting has two advantages: the fasting periods allow fat consumption and cell regeneration while the eating periods are marked by a greater appreciation of one’s food and a greater awareness and interest in healthy eating – and the impact on one’s figure and appearance is soon apparent.

Toprosemary with flowers isolated on white background

7) Health benefits of Intermittent Fasting
The health benefits are very similar to long-term fasting:

    • reduced blood-sugar
    • reduced blood-pressure
    • reduced cell stress (cellular damage through oxidation)
    • reduced insulin levels
    • reduction in inflammation processes
    • reduction in cholesterol and triglycerides
    • reduction in body-fat
    • improved immune-system
    • increased cellular stress resistance
    • improved cellular regeneration and elimination of degraded cells
    • increased production of growth-hormones
    • increased life-expectancy.



8) Why is Intermittent Fasting healthy?
We are biologically adapted to fasting because our ancestors did not have the easy and frequent access to food which we have today. The possibility of eating unlimited quantities at any time of the day is very new for mankind and first occurred in the western world during the 20th century and has culminated in the universal and excessive availability of food that we know today. This (initially positive) development has led to a multitude of problems such as a growing number of “modern” illnesses, environmental problems and the mistreatment of livestock on an industrial scale. Fasting and Intermittent Fasting also provide answers to the ills of our modern society.

With respect to our modern „civilisations illnesses“, one can consider Intermittent Fasting as a kind of regular „house cleaning“. Just as we regularly vacuum our homes and take out the garbage, Intermittent Fasting performs similar functions in our bodies.

After 12 to 14 hours, our cellular glycogen reserves are exhausted and our bodies start to break down proteins in order to access energy. These proteins are primarily damaged or defective cells and superfluous and potentially dangerous proteins (Advanced Glycation End-products or AGEs). Healthy cells are endowed with a defense function which protects them from being metabolized. Healthy cells are not only protected during this phase but they also undergo a profound regeneration. Thus fasting favours the elimination of harmful substances and the regeneration of healthy cells. Once the defective and harmful matter has been consumed, the body turns its attention to burning fat for fuel.


9) Further benefits of Intermittent Fasting in daily life
    • Time-saving

Skipping a meal means less time spent shopping, cooking, eating and dishwashing.

    • Money saving

You save money by eating less.

    • Conscientious Eating

Of course, it might be better, for both our health and our environment, if we, in stead of saving this money, reinvested it in better quality foods such as in organic and Fairtrade products.

    • Greater Flexibility

For instance: I have to attend a birthday party …

-> If this coincides with a normal eating period, I eat as much cake as I like without a bad conscience
-> If this coincides with a fasting period: again, I eat as much cake as I like without a bad conscience but I delay the next meal accordingly, drop it altogether (dinner cancelling) or skip breakfast the next day.

Eating cakes and fasting

    • No bad conscience

Why should I feel bad about eating? I enjoy my shopping, my cooking and off course, my eating; feeling bad or frustrated about eating is a thing of the past! Because of the flexibility of Intermittent Fasting, I do not have to avoid any particular foods and need not lose sleep over a slice of cake or two. The key is simply to allocate regular pauses for your body to regenerate!


10) Studies on fasting and Intermittent Fasting

Studies on animals and humans show that fasting could prevent “civilisations” diseases such as Alzheimer’s, cancer, metabolic illnesses (e.g. type 2 diabetes), heart, artery and joint diseases as well as allergies; furthermore, ageing processes appear to be slowed by fasting.


Fasting: Molecular Mechanisms and Clinical Applications
Klinisch wissenschaftliche Grundlagen der Fastentherapie
Award winning speech: Fasting, longetivity and cancer
Sirtuins in Aging and Age-Related Disease
BBC Documentary »Eat, Fast and Live Longer«
ARTE Documentary »Fasten und Heilen«

Collection of fresh fruit and vegetable slices on white background