Having looked at the nutritional content of one of the Herbal Life shakes, the second ingredient on the list is fructose (sugar), it also lists dextrose (sugar) and honey powder (sugar), adding up to a whopping 21.5g of sugar per shake when made up with milk. Doesn't sound suitable for diabetics (or anyone else really) to me!
Steve, I know that losing weight the traditional way is a hard slog, but you are far better off following a healthy, balanced diet, rich in protein, vegetables and some fruits, 'good' fats and a reduced amount of complex starchy carbs. Quick fix meal replacement shakes don't train you to make healthier food choices which is what we all need to do if we're going to maintain a healthier lifestyle permanently. Also, the synthetic vitamin mixes used in such replacements are not a patch on the vitamins and minerals you will receive from eating natural foods.
Have a look around the forum and you will find plenty of inspirational posts by people who have lost weight doing just that - whether it's a reduced carb diet, or a low GI plan that's best is something only you will find out by trying it out - but you will be better off by giving the meal replacement shakes a wide berth.