We are missing a lot of context - much of which you can't supply here even if you wanted to. For example, it seems entirely plausible and not exactly rocket science that not eating the wrong foods (for a given person - what "wrong" means may vary widely and wildly depending on their context!) is better than eating it. For an example (of the example), if you eat a lot of high glycemic index foods it's not hard to guess why your blood sugar is doing better without it.

This is the problem with all those reports from people who say they are doing so much better during a fast.

You are right on every point. Water fasting was not Dr. recommended but the profound positive effects were documented by the follow on tests they performed. No one seems to know why it "worked". I dunno if it is knowable at this point. But one thing I do know I was very ill and now I'm a lot better and fasting was a key reason why.

I'm reminded of Ignaz Semmelweis, the doctor associated with hand-washing. Even though he demonstrated clinically that hand-washing reduced sickness/mortality, it took decades to catch on because, "it didn't make sense." I.e., there wasn't sufficient theory to explain WHY it worked.

Just a personal anecdote, but I was getting colds and flu-like symptoms several times per year for years. People I knew often commented on how often I was ill. I did a 3-day fast two years ago, and haven't had much more than a scratchy throat for about two days since. It could be coincidence, but other people have noticed and commented on my healthier state. I haven't significantly changed my behavior otherwise.

I'm not doubting that what you say is true, but I wouldn't necessarily draw a simple cause-and-effect arrow between a single fasting event and your improved long-term health. The fact that you even began a fast suggests you became increasingly conscious of your health at that time and were looking for ways to improve it. Perhaps you also decided at that time -- maybe even subconsciously -- that a healthier lifestyle with better eating and sleep habits would be in your interest. In other words, there is a correlation between your fasting event and your improved health, but not necessary a direct causation.

This reminds me of the reasoning used by a lot of people who've made the link between autism and vaccines. "My child was vaccinated and shortly thereafter she became autistic!" Yes, but children are also vaccinated around the age when the first signs of autism become apparent.

Human minds are incredible pattern-matching machines. Unfortunately, they're so good at it that they often deceive themselves.

It has to be a coincidence. I can't imagine what the health benefits of a single 3-day fast could be that they would be so massive as to change your entire health for years.

A change in gut bacteria could potentially do that. However, normally that is quite difficult to change long term. I seem to have a collection of gut bacteria that give me bad gas quite often without sticking to a very strict diet and I found a few months ago that a five day fast reset that as well as antibiotics. However, either way it gradually returns to the way it was (most of the way back after three months). Good to know that three days of fasting helps some people, since that is much easier than five :/.

Quite possibly. However, if I found myself in a similar situation years from now, I would try it again.

Interesting 2 years ago I was up for a operation to implant a tube for dialysis after the 3 day fast before going into hospital my creatine levels improved to the point they canceled the operation.

Wonder if this will happen this time around :-)

It should be noted that going from eating a lot of unhealthy food to a 24hr fast might be a little on the dangerous side for some.

The first time I tried it after about 12 or so hours I felt like I was going to pass out. So I ate something to stablize myself. After eating healthier for a while it's much easier to attempt.

I was on a strict diet/exercise regime for seven years before I tried fasting.

I had the same experience. I've been doing intermittent fasting for several months, and after a while I felt that hunger doesn't bother me that much anymore, so I decided to go for a three day fast. I do get slightly elevated blood pressure from time to time, but on the third day of fast I noticed that it dropped to lower than 120. I did a bit of googling, and found that there even were some medical studies looking into effect of fasting and lowering of blood pressure.