I'm with you on this: Anyone that rejects clinically studied treatments in favor of "alternative" treatments is an idiot.

That said, the keto diet is being studied clinically and preliminary research does seem to indicate that it has an effect. So it may be an "in addition to" treatment. That said, the news isn't entirely good:

https://www.cancer.columbia.edu/news/study-finds-keto-diet-c...

The bottom line is ask your oncologist. They're probably paying attention to these keto studies and they know more about your cancer than HN does.

Are you sure about this? There is data to back it up in The China Study https://en.wikipedia.org/wiki/The_China_Study and mentioned in the Forks over Knives documentary. That's more about prevention, but it has a measurable impact on cancer rates, I don't see how that could be classified as no impact.

I don't understand unreasonable positions like this.

Nobody is saying that people should stop "real" treatments or that diet must be the primary or sole focus for treatment. But given that a change of diet (a) costs nothing, (b) has no downsides, (c) potentially may work it seems strange not to do it.