I've not read the actual book itself & press reports are well known for being a sensationalist croc of shite a tad left of the truth, so I'll reserve proper judgement based on press reports.
That said, if the books cover is all that the fuss is about, them she isn't cutting out all carbs, just wheat & processed carbs along with other foods known to be hard to digest, or potentially harmful in some way is not the same at all as the press headlines would have us believe & suggests any quotes are taken out of context.
I've eaten this clean diet way myself, its nothing new even if she does keep banging on about it as if she's some directional food guru it my case is was as a result of kidney trouble & no real medical answers or help, so I set about helping myself & ate this way for a several years - it made HUGE difference to my health & turned the kidney problems around, even healed some of the damage caused by recurring infections of no know source - much to the puzzlement of my doctors.
Even slackening off & eating a more "normal" diet after a few years didn't bring the problem back for many years - though more recently it has come back, though not infections & ironically its now all looking to be as a result of celiac disease - I'm currently eating a gluten load diet - my normal diet is a very healthy one, low in wheat - loading up on wheat is causing a heap of symptoms - I can really feel the difference
DD eats a similar diet, not fanatically so, she eats sweets, wheat etc occasionally, but she too has health problems & eating a clean diet like this helps keep her healthy too