Guess I'm talking about clinical evidence?
I think the evidence is staring us in the face. It is not easy to make our bodies work in ketogenic mode. We have to almost eliminate carbs and protein from our diet because our bodies have an inbuilt preference for the glucose route via Citric Cycle, and fat burning is a last resort protection mechanism.
We are adapted to all three mechanisms being able to support life, but our brains need pure glycogen, and our body has to work hard to produce it when in ketogenic mode by synthesising it from proteins if carb is missing.
Brilliant design of a closed loop control system -Its like having a multifuel boiler that runs on gas (most efficient and economic), oil, electric (most expensive) or wood burning (needs logs stored and ash disposal, so a faff),
Normal (non-diabetics) can use carbs (but tend to overdose in modern life) and it is not normally a problem, For us diabetics, our main regulating system (insulin) has developed a fault, so our control goes wonky. We can use LC diet as a work around to restore some semblance of control, but this requires significant alterations to our diet. Its a bit like the adaptations made to transport during the World Wars with gas bags on the roof of buses etc
LC diets work for us, and we are right to champion them and decry the Eatwell advice, but that is our choice and not a new religion. I use LCHF because it makes sense to me and ticks most of my boxes, but I try not to be a zealot for the cause. I will query aspects of it and debate its merits, but I try not to say it is the answer to a maiden's prayer.