Let's not forget Drs. Dan and Mary Eades who co-authored Protein Power and also use the low carb diet themselves and recommend it to their patients with no reported ill-effects to health long-term.
Then there's Dr. Richard Bernstein, a type 1 diabetic who has been using a ketogenic diet to control his diabetes for more than 40 years (with reversal of previous diabetic complications) and has been using it to control diabetes in his patients for more than 20 years. Again, no reported ill-effects to health unless you consider weight loss and a reduced (or no) need for medications to control diabetes an ill effect.