I have friends and sisters who go to Slimming World and they are always trying to get me to go, but looking at their meal I know they would give me high blood sugars. In my experience no diet I've followed helps me lose weight long term if it contains a 'normal' amount of carbs. I'll lose half a stone, but then my body seems to adjust ad I slowly put it all back on and then a bit more. 30 years of doing this took me to 19st. My 2 sisters have been going to Slimming World for about 15 years. One sister has been half a stone off her goal weight for most of that time, the other has yoyo'd between 13 and 11st. She's not 5ft, so has for all that time still been overweight, and she's paid for that privilege!
Since I've been on this website and following a low carb diet I have managed to lose 3st. It's very slow, as I've not really been dieting, but rather changing my diet to get my blood sugar controlled. It's been hard to get my head around after a lifetime of low cal, and I made some mistakes with things that didn't work for me, like being patently unable to control myself around nuts, so snack on them too much and have lots of added cals!
Look on here at the low carb forum. Lots of good advice and recipes, but not much of it fits with Slimming World and when you take in your taster dishes to a meeting, which have cream and cheese and bacon, don't be surprised when everyone gasps!