'Reverse' is quite a strong term to use in this context. I do not find 'reverse' in the medical dictionary, but when medical articles talk about reversing alzheimer's, for example, that means undoing the damage that it has already done to the central nervous system. Can a keto diet undo the damage that diabetes has already done to someone's blood vessels, nerves, eyes, kidneys, etc? Better verb for what diet can do for T2 diabetes would be 'treat' or 'control;' If 'reverse' means something more than 'treat' or 'control', what is the bonus extra? Is there any reason to think that additional damage does not accumulate atop that previously done when blood glucose increases because treatment is discontinued or control by diet is otherwise insufficient.