This is not to discredit or be negative but this has been my experience.
I started the FD to help with glucose levels.In my 40’s and my BMI was 24. Thin frame male. My fasting glucose levels have ranged from 100 to 107 over several years. Up and down. Its been a year since I started the fast.

I lost weight right away. After 6 months I had a lost few pounds and had A1C test and a fasting glucose. The glucose was 102 and the A1C was 5.6 (high normal). Previously it had been 5.7.

I took this as a good sign. After a year I had another test. Glucose was 104 and A1C was 5.7. Small increments for sure but still back above normal. And my weight was back to where it had been before I began.

In a nutshell I now believe;

I was eating more on my non -fast days and like most diets I put the weight back on. basically fitting it all back into the lifestyle I wanted.

Its more than likely any benefits are related to weight loss.

There are still no easy answers. I stopped the fast two weeks ago and have gone back to watching what I eat and adding another day of excercise. I have lost weight already. In a few months I will check my A1C again and see.