This is not a medical advice. It may not be a safe option for you. Please contact your physician for personal advice.
I am 50 year old 6’1″(185cm) male, medical doctor. Over years I had my weight gradually reached 310 lb. (141kg). I started very low carbohydrate diet in 2014. After initial weight loss of about 40 lb.(18kg) I gained it almost all back. In 2015 since I did water and salt fast for 30 days without significant effort since I was already in ketosis already for quite some time. I drank water whenever I wanted it and took salt from hand whenever I wanted. In order to retain that water I need to take salt. I also dissolved Centrum Silver multivitamins in water and drank it couple times a week. I continued to work as a physician in a very busy practice. After 30 days I stopped fasting because I felt weak and had difficulty concentration at work.
To break my fast I avoided carbohydrates, (no sugar, no fruit, no juice, and no starch). People have complications from re-feeding because glucose raise in blood stimulate insulin production and severe electrolyte shift in the body that may cause irregular heart beat and very rarely death.
I ate small amount of broth, eggs, cheese. I took Thiamin, Magnesium Oxide, Potassium Chloride and Potassium phosphate for the first several days.

In January 2016 I fasted for 35 days. I consumed water, salt, multivitamins. I broke my fast with broth, milk, heavy cream, eggs, very slow, small amounts, and several days. Again, I supplemented re-feeding with Thiamin, Magnesium, Potassium, and Phosphorous.
During that fast my weight went from 321 lb. (146kg) to 266 lb. (121kg).
Since then I started fasting every first week of every month. I did nothing to break a week long water and salt fasting, no vitamins, regular activity, no exercise. I ate anything I wanted, but kept very low carb diet. Every month I gained about 30 lb. (14kg), then lost 22 lb. (10kg) during wasting week.
It is quite easy to fast if you are on low carb diet. But it is not enough. Every month I gain 8 lb. (4kg), approaching my initial weight 321lb (146kg).
Starting next month I will do two 6 days fast. On the first and 15th day of every month.
This is not a medical advice. It may not be a safe option for you. Please contact your physician for a personal advice.

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Here is my weight this year. I did not check it daily in January, so it is a straight line. Every time I fast it goes down. Every time I eat, it goes up.

http://i53.photobucket.com/albums/g70/muslofraslv/Weight_zpsxswsmrhc.png

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I have no high, diabetic glucose spikes during days of eating food. It is natural for everybody to have blood sugar variability between meals. I try to stick to green leafy vegetables, avoid starchy vegetables almost completely. I eat berries and seeds. In other words carbs only where they come with a lot of vitamins and other nutrients but not calories. Fruits usually contain a lot of glucose and fructose. This keeps my insulin low.

I have no “fatphobia” whatsoever. I am minimizing protein to non-caloric needs. This keeps my mTOR activity low. Most of my calories come from fat. This allows me to stay in ketotic state and fast without effort any time. I prefer fresh meat and fish without nitrites/salt preservatives.

I am a Family Practice physician. I do this diet on myself only.

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All most all obese people are leptin resistant. Leptin production is a problem with extremely rare people with genetic deficiencies (one in a million).

Portion control does not work for me. Judging by trials done with thousands of other people it does not work for others either. I mean long term. I stopped that nonsense with calorie count long time ago. I eat till I am not hungry anymore. Like most of us.

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It is simple. I don’t want to be bothered to count calories because it is bothersome and useless.

In the past I tried to memorize caloric values of foods, used software to constantly monitor caloric input and output. And what? sure, you can estimate the difference and how much you “should” eat daily. But there is a reason it does not work for thousands of people undergoing weight reduction trials. The reason is because it is a hunger that determines amount of food we eat total over period of a month or a year. You may try playing daily games of eating less, eventually your body will win. Thin people are not thin all their life because they count calories all their life. They eat until they are not hungry anymore. Obese people do the same. But obese people have that “set point” for weight wrong. My set point over many years climbed to 320 lb. I made this set pain irrelevant.

I figured out how to eat less over long period of time without being hungry and without counting calories. My weight shows where I am now. Without testing I know my insulin is low, my mTOR is down-regulated, my leptin is going down following shrinking fat cells.

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It is simple. We have a choice: either count calories for the rest of our lives or do repeated water fasting for several days. Zero calories during fast, any calories dyring normal life. It is very difficult if you on high carb diet. But once you enter ketosis it is easy to switch to fasting any time.

My “set point” weight was 320 lb(145kg) for quite some time. It is 284lb(129kg) this morning. I don’t to struggle daily with it. I eat normally. Once or twice a month I fast for a week. This allows me to adjust my weight any time to any number.

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Constantly regaining weight is inevitable. It is not your choice or mine. You regain if you count calories or water fast. Fasting one week at a time is perfectly safe. There is a lot of evidence that shows that fasting is good for your body.

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Weight loss. This is what I am trying to achieve.

I am doing it now and I realized that I can be in control of this illness. I tried to do it for the past 30 years. I tried pretty much everything short of barbaric surgery. This year is a first time when it started working for me. It happened when I stopped being afraid to fast for several days.

I am not inviting you to do it. Not interested? Ignore it. Move on. My goal is to inform those who are interested. Obesity kills a lot of people every day. The minute I realized it could be useful to others I shared it.

I hope others will find something that worked for them and share it also. Medical trials done after hypothesis is generated. Internet crowd-sourcing can generate hundreds of them. This is the fastest road to cure.

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Yep, exactly. I lost initially 56 lb (25kg) during month-long fasting, then started gaining. So, I adjusted length and frequency of fasting for my need and my weight started going DOWN. I will do week-long fasting on 1st and 15th of every month for a while, then reduce it, depending on my weight. I will be reporting my progress.

I am glad to hear that keto diet worked better for you. I don’t see contradiction between 5:2 diet and keto diet with water fasting. The difference is that you don’t count calories. During fasting calories count is zero. During non-fasting you eat as much as you want, except carbs. Carbs should be as close to zero as possible. Always. Keto diet with or without fasting is just more efficient and more simple way to lose weight. I am on 7:7 diet. Seven days low carbs, seven days water fasting.

I keep losing weight. I lost initially 56 lb (25kg) from 322 lb (146kg) to 266.6 lb (121kg) during month-long water fasting, then I started gaining with once a month 7 days water fasting. So, I adjusted fasting to every other week. I lost everything I gained and more, down to 260.6 lb (118 kg) Total weight loss this year almost 60 lb (28kg). I would lose more, but muscle training caused me to put a lot of muscle weight. Yesterday I started another week of fasting. I expect another personal record. I will publish my weight graph in 5 days.