We can't answer this confidently, the way I would say it is: there isn't strong evidence to support the idea that either is better.
> Given my current understanding from all the intermittent fasting hype lately, it is indeed better to eat big meals rarely rather than small meals frequently. For some reason, your post got me slightly confused because I lack the necessary knowledge to have a proper model about nutrition in place.
The IF people (along with the Keto people) use a variety of tricks to try and prove their point. There is absolutely not a single paper showing calorically balanced food intake has different clinically significant outcomes. Period, full stop etc. There are tons of papers saying things like if you force people to eat in constrained windows they eat fewer calories (or if you force people to eat high fat diets they eat fewer calories etc.). Those are all useful outcomes: they are "compliance hacks." But they idea that any of these are significantly metabolically different is not at all supported by the science.
As for yourself: nutritional science is weak, and if the nutritional science says do something, and you observe a bad outcome in yourself from doing it, I'd take your own personal data over the nutritional science, frankly. For instance: fiber is a great modulator. If you go to a GI specialist and say "I'm having dietary issues," increasing fiber is usually the first thing they recommend. But also, sometimes that doesn't work and then the next thing is decreasing fiber (FODMAP diet). So it's really hard to make sweeping recommendations because the body is so complex and nutrition involves so many different cooperating systems that can all go slightly wrong.