The author seems to have a weird axe to grind with the keto diet. The link that is supposed to go to the study just goes to another summary article of the study written by her.

Low carb dieting is based on some pretty solid evidence, and it's going to take more than this to convince me it's a bad idea to remove carbohydrate derived glucose. It also gives me pause when the author says things like "low carb diets cause tumors to grow". Where's the evidence?

Anecdotally, I have a friend that's no longer prediabetic because he switched to a ketogenic diet, and numerous people have told me the diet has improved their overall health.