As someone who’s lost 15 pounds since Christmas doing nothing but eating in a restricted 2 hour window rigidly most days. This doesn’t surprise me. Long low blood sugar periods and it’s much easier to get a single window of eating under control.
I encourage you to try IF for a longer period. A week or two. There’s an adjustment period after which it becomes easier and then becomes the norm.
Also I find low carb, but not necessarily keto works better with IF. Essentially the goal is not to spike insulin too often.
The reason IF works for me is that I know I can eat pretty much what I want so long as it's reasonably healthy (lots of veg, fruit) and I only do that once a day.
A traditional calorie controlled diet works also in the short term but it's miserable and, eventually, I break just as, anecedotally, most other people do too
The body is a complex system, and different people's bodies work differently. Really, what I want to know from a diet study is were their negative effects, and did it work for a significant amount of the people. Ideally, for those who it seems to work, do a longer term study to look for negative effects and long term results for people who stick to to it. If you get enough of these studies, and I'd like to change my diet to control my weight, I can try things until I find one that seems to work for me, and have some confidence that it works long term for people who it works for.
One diet to rule them all is the same thing as everyone should run the same HTTP server. I love apache, but different systems work better with different servers.
What I am trying to say is, you are totally right here. I suffer from IBS, and if I just try IF for one day my entire guts go really nuts (I have mixed type of IBS).