To eat or not to eat
It is pathetic that a day of junk food is accepted and a day of abstinence is demonized.
A simple solution to diabetes is right in front of us but apparently the will of some lobbyists to make money is stronger than our motivation to use common sense.
Yes, it is work to keep your weight after a fast, but it is not automatically more work than after any other dietary change.
Fun Fact: Participants in the american reality show "The Biggest Loser" had lost about 58.3 ± 24.9 kg as part of a reasonable weight loss plan (less and healthier food, more sports). After six years, 14 out of 16 participants had not only gained 41.0 ± 31.3 kg of the lost weight back, but their metabolism had slowed down to such an extent that further weight loss was significantly impeded. 
There is a "weight loss program" called Intueat where you can learn how to listen to your body and only eat when you really feel the need and hunger. The fact that people have forgotten how to listen to their body is understandable, but not that they have to pay 93€ a month to relearn such a thing. And I don't blame the individual, I see this as a failure on a political level.
Sadly, it is only through the consumption of offshore media that people start to perceive fasting as a completely legitimate weight loss method.
How unworldly does a being have to become in order to see the renunciation of food as "abnormal" when someone is overweight?
Unfortunately, there are only a few sources out there that spread this knowledge. Why should anyone market such an idea anyway? Who can profit from it? Obviously not the industries.
People of my age or younger and neurodivergent people are not allowed to talk about this topic, because it could be an indication of potential eating disorders. In reality, society simply does not dare to face up to the responsibility of eliminating one of the world's biggest epidemics. >>Diabetes Fun Facts<<
And after self-doubt and uncertainty have been defeated, the idea of fasting could also be approved by normal-weight people. After all, it has long been proven that occasional fasting is beneficial for everyone.
The following is a cheatsheet for all those who want to fast, for future me if I have forgotten how and why I´m even doing this. And lastly, for all my acquaintances and friends that question my life decisions.
Without guarantee that all information is correct or up to date.
Before the fast
It is recommended to prepare for fasting by starting to going ketogenic (many fats, no carbohydrates) for 4-5 days before the fast begins, so that you give your body time to switch to fat as fuel, as the body also primarily burns fat during fasting. If you are already in ketosis, there will be less headaches and less feverish feelings due to lack of sugar during fasting.
Fasting is also a thing that one can and should definitely train. Once you have mastered 18 hours, 24 hours is not difficult.
During the fast
After 16-18 hours of abstinence the ketosis starts and from here on the consumption of minerals is indispensable:
Salt or Sodium is the most important mineral of all. It should be remembered that when the body is not fed, the glucose (in the form of glycogen) in the glycogen stores is used up to produce energy. Glycogen, however, binds water (2-4g water to 1g glycogen ). What does this water contain? Sodium!
So if we don't take in glucose, our body has to make do with glycogen and when it breaks down, it also rinses the water with our valuable sodium.
As if that wasn't enough, our liver has difficulty absorbing salt during fasting because insulin normally helps to regulate it. And our insulin levels are quite low after just one day of fasting.
So the body has to rely on us to take in more salt.
What is sodium good for anyway? It regulates our water balance, plays an important role in the excitation of nerve cells, influences our blood volume and is important for bone mineralisation! 
As soon as you get headaches and feel physically weakened despite fat adaptation, you realize how important salt is.
Recommended amount: 5g salt/day or 2g sodium/day
I myself consume on a fasting day about one teaspoon of Himalayan granulates and 1/4 teaspoon of baking soda.
Magnesium is excreted as well and if we do not consume any for a longer period of time it can become quite problematic. Magnesium is virtually the antagonist of calcium. Both substances regulate and stabilize the tension between excitable nerve cells. Now, if there is less magnesium, the calcium has more influence on the nerve cells. And calcium is responsible for the contraction of the muscles. So a magnesium deficiency can lead to tension, nervousness, cramps and restlessness .
Recommended amount: At least 300mg/day (w), 400mg/day (m)
Magnesium can also be absorbed through the skin, so you could for example treat yourself to a nice footbath with magnesium sulphate. I mix 2g magnesium citrate with water and drink it.
Potassium is the dance partner of sodium. They should be at eye level, so that the regulation of blood pressure, the control of muscle activity, but also the bone mineralization succeeds.
A potassium deficiency is really not to be underestimated. It also leads to tension and cramps and in the worst case it can lead to cardiac arrest.
Recommended amount: around 2600mg/day (w), 3400mg/day (m).
I take potassium gluconate.
As soon as you have minerals in your body and regained energy, the 20 hours are quickly over and then the ketosis is in full swing. Watch two good films until the 24 hour mark is passed and then the autophagy can begin.
Autophagy was the main reason why I decided to fast. It's a very interesting process: the body doesn't get any food, so it has no other choice but to eat itself. The body cells begin to break down their own proteins and lipids to create new components for themselves. And fortunately, they prefer to do this with defective proteins and lipids. So the cells clean themselves up.
This is of course a good thing when you consider that a great deal of diseases are due to degenerated or clogged cells.
Autophagy takes place in every organism, but decreases with age. A reduced autophagy increases the risk of developing tumours  and neurodegenerative diseases . Thus, a conscious initiation of autophagy can prolong the life or health span of the organism. Critical Success!
Autophagy does its thing and in the meantime we wait until about 48 hours have passed before we reach the next milestone:
The production of our growth hormone Somatropin has now quintupled since the beginning of the fast! 
Especially when you get older, your body produces less somatropin. Which leads to increased body fat, reduced muscle mass and bone mineral density, reduced quality of life and expectations.
Get a good night's sleep, because after 54 hours another great thing will happen!
We have increased insulin sensitivity!!! And it's exciting because when the body is insulin sensitive, it needs less insulin for certain reactions and handles the carbohydrates it receives better. Thus the regulation of the blood sugar level is significantly improved. A low insulin sensitivity (=insulin resistance), on the other hand, can induce an overproduction of insulin, which in turn raises the blood sugar level. 
Insulin resistance is often the cause of type 2 diabetes, but also of cardiovascular diseases.
The highlight comes after 72 hours of fasting, when old immune cells are broken down and new ones are built up .
After 72 hours, all these processes continue to run but the efficiency decreases exponentially and eventually reaches a plateau. What remains is fat reduction. Not bad either, right?
One thing that is still super important during fasting:
There is this trend "Dry Fasting" where you do not consume any liquids. It is supposed to intensify certain processes, which are also caused by water fasting. There is, for example, Ramadan intermittent fasting (RIF), which has an anti-inflammatory effect , is said to have positive effects on cholesterol levels  and to increase insulin sensitivity  even more, but in my opinion the ROI is simply too low in view of the fact that dehydration can occur quickly. An Extended Dry Fast is even more dangerous. There are indeed people who fast for more than 72 hours without water, but I have read few positive reviews about it in the last year.
Recommended water consumption is 2-4 litres per day.
On normal days I drink around 3 litres of water, but on a fasting day I can get by with 1.5 litres.
Breaking the fast is not a trivial matter, as the body is particularly sensitive to certain foods after a fasting cure. And that is the beauty of fasting. When breaking the fast and also afterwards, you can see which foods are particularly good for you and which are not.
It is to be said that fasting can become quite an addiction. So always stay alert.
I like to extend my time interval on weekends and I plan to do at least and at most one Prolonged Fast (48-72h) per month in the future.
I could write countless lines about what fasting does to your mind, but that might be too much... and too personal.
Why don't you try it yourself (after consulting your doctor).
Step 1: Don´t eat. Step 2: ??? Step 3: ??? Step 4: Profit!
 Persistent metabolic adaptation 6 years after The Biggest Loser competition
 Water Weight: What is it and why does it matter
 Overview of Sodium's Role in the Body
 Welche Aufgaben übernimmt Magnesium im Körper?
 Induction of autophagy and inhibition of tumorigenesis by beclin 1.
 Autophagy and Alzheimer’s Disease: From Molecular Mechanisms to Therapeutic Implications
 Augmented growth hormone (GH) secretory burst frequency and amplitude mediate enhanced GH secretion during a two-day fast in normal men
 Progressive alterations in lipid and glucose metabolism during short-term fasting in young adult men
 Prolonged fasting reduces IGF-1/PKA to promote hematopoietic-stem-cell-based regeneration and reverse immunosuppression.
 Effects of Intermittent Fasting, Caloric Restriction, and Ramadan
Intermittent Fasting on Cognitive Performance at Rest
 Is Ramadan fasting related to health outcomes? A review on the related evidence