The existence of the study may entice participants to fast for a long period in exchange for attention or (relative) fame, while they wouldn’t have done so without it.

It also may put pressure on them to continue where they normally would have stopped because they feel pressure because “those scientists invested so much time in it”.

And of course, they may suffer long term health effects, even if they fast for a period that typically doesn’t have any on subjects.

You can see these kinds of ethical issues clearer by exaggerating. Replace “fasting” by “being hit in the face”, for example. What’s wrong with looking for volunteers who want to be hit in the face every hour for weeks?

I have done lots of alternative stuff to deal with a serious medical condition. I have done so very successfully. I also did it without external pressure to stay a particular course, etc.

People when watched behave different. People under contract behave different.

It is one thing to take notes when someone does this voluntarily. It is quite another to put people under contract for something like this.

Fair point. I thought more on the lines of "we search people who want to fast. We will provide medical supervision and a controlled environment where you can do that, while we take notes. If you want to quit, you can at any time." (I assume with contract you mean something like "you have to fast for x days, if not you are in breach of contract" - is that correct?)

I just mean a contract agreeing to a study at all. "What gets measured gets done." Etc.

I am under the close supervision of my 30 old son and have been since he was 13. It's a completely different dynamic than reporting results to a doctor or lab for a study.

I believe that the ethics board will not allow voluntary harm, if as a scientist you believe that the procedure is harmful (beyond done reasonable threshold, as everything is harmful in large doses...)

This is an interesting point, why do you suppose fasting is considered harmful by anyone? I feel there may be some historical propaganda against it at play here.

> ... why do you suppose fasting is considered harmful by anyone?

As noted by another poster, extreme fasting is sometimes fatal.[0] I've also heard elsewhere that it can be fatal and a physician should be consulted before fasting more than a couple of days.

[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2495396/

I am aware that extreme fasting is dangerous, but so is extreme water drinking.[0] But fasting in general seems to be stigmatised.

Dr. Jason Fung [1] has some fascinating videos on Youtube about why fasting isn't bad. I am just curious why there's a mainstream view that it's bad and the exception is that it's good, vs the other way around?

[0] http://www.nbcnews.com/id/16614865/ns/us_news-life/t/woman-d...

[1] https://www.youtube.com/watch?v=v9Aw0P7GjHE https://www.youtube.com/watch?v=tIuj-oMN-Fk

Edit: Dr. Fung points out one common misconception that fasting causes muscle to be eroded.

I think it's probably a combination of the knowledge that extreme fasting is dangerous and the myth that your metabolism plummets as soon as you skip a meal.

When I was in middle school, I remember my friend's older sister being on some kind of snack diet that was supposed to keep metabolism high by never going more than an hour or so without food when not sleeping.

I seem to remember Brad Pilon in "Eat Stop Eat" briefly mentioning the origin of the myth that your metabolism tanks rapidly if you skip a meal, but I could be wrong.

I do intermittent fasting myself, and it drives me a little crazy when my wife tries to convince me that it's bad for my health to skip dinner once in a while on one of my non-fast days.

Besides the video he has written extensively and in depth on the subject on his blog and in books https://idmprogram.com/blog/

It's unethical to study extreme fasting as you have to ask someone to put themselves into a dangerous situation. Someone doing so voluntarily (against advise) and being monitored is fine.