There are A LOT of research and videos out there not only on intermittent fasting, but the myriad of diet/health approaches. Because we are so genetically diverse as a species, there are clearly approaches that work for some that won't work for others. There is also a dearth of gold standard research due to cost and time constraints. Here's a nice piece of research about evidence-based medicine:
Also, while I do believe that there are universal truths about how our physiology works I try to keep on open mind by reminding myself that "Truth Precedes Proof." Yes. I made that one up after reading Bill Bryson's where he quotes Alexander von Humboldt
“There are three stages of scientific discovery: first people deny it is true; then they deny it is important; finally they credit the wrong person.”
With all of those qualifications, I still have a simple scale for evaluation content:
Level 1 - Peer Reviewed Research Level 2 - Reputable Brand Level 3 - MD or Science PhD Level 4 - Health-related accreditation Level 5 - Passionate and diligent curator ←ME Level 6 - Fanboy/Anecdotal
I try to keep my references to Levels 1-3. Again, it's very likely that Levels 4-6 are sharing information that will ultimately be proven true, but for now, I will leave it to you to find and evaluate those. If I do cite a Level 4-6 source, I will be sure to mark it clearly. E.g., for intermittent fasting you will come across a Dr. Eric Berg who as some of the most popular IF videos online. He does a nice job summarizing existing ideas, however, he also includes as fact some ideas that I haven't found to be proven yet. It also hurts me that is espousing IF protocols as "Dr. Eric Berg" when he is a chiropractor.