If anyone tries to tell you they are fad diets and there is no research to say they are safe, or even true - you could refer them to the book 'New Diet Revolution' by a certain Dr Atkins. Despite all the claims, the low carb way of eating Dr A devised worked for thousands of people, including diabetics, and if there isn't evidence from his clinics, there ought to have been - there should have been if people were not so dead set against the idea that carbs might not be a healthy choice.