I've been doing the 16:8 for 2 weeks, with black coffee in the AM, first meal at lunch. Does seem to be beneficial as I have good energy after lunch and not needing more caffeine. And not feeling bloated, etc. Starting to note some weight loss, but likely that is a result of cutting out the mindless eating - at least until noon. Not intentionally reducing caloric intake.
Also seems to be a good transition to a few days a week of lower intake (ie moving towards the 5:2 thinking). Or possibly trying the fasting mimicking diet (see Valter Longo/ USC research). That said the 16:8 is easy whereas the fmd, etc is more work.
I'm decades past this point, but found a detailed study on an 8-week trial of the 16:8
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5064803/
In short, they found decrease in body fat and blood glucose when the only dietary change was time of feeding.