Many of my friends (including myself) have joined Slimming World over the years. There is a trend - they all lost quite a substantial amount of weight over a relatively short period of time. Kept it off for no more than six months, then ended up putting it all back on... Sometimes more.
Looking at the plan, it doesn't look like a sustainable, long term lifestyle and it doesn't even seem like a healthy way to lose weight. Viewing treats as "syns" seems dangerous. Encouraging in group for members to eat unlimited pasta is ludicrous. It's essentially a calorie deficit just like every other method of losing weight, but encourages members to view food in a negative way.
Also, the whole experience is based on the number on the scales, which may fluctuate week-on-week and not actually be anything to do with fat loss.
AIBU to think that Slimming World is all a big con and doesn't work on a long term basis?