I tried the slimfast diet many years ago and it worked after a fashion. The point is you can't stay on any diet for the rest of your life. 1) it will cost a fortune. 2) you will get so BORED!!. The best diet to get yourself on is one that you will be able to stay on, ordinary every day food. Cut out or cut down on the things that are bad for diabetics. Eat plenty of what is good nutritious food. If you are a veggie or vegan adjust your diet to suit. If you have allergies to other ingredients, do likewise. And while you are discovering that you can eat a lot more than you thought possible, get in some exercise too. If you are overweight/out of condition, make it gentle exercise. Nothing to overstretch the heart. Search for the words. 'eat less. move more' and you might get some info on someone who lost 17 stones doing just that. I have lost 5 1/2 stones by doing what I have just preached.