It's not complicated. I've lost around 3-4lbs a week on average. But I'm a bloke with three stone to loose so it will be perhaps a little faster for me than others.
I'm sure if you google Slimming World, you'll find some lengthy reviews that help to describe the diet in more detail.
But basically there are three steps to the diet:
First, you choose a red or green day each day. If you choose a red day, you can have unlimited lean meat, poultry and fish. If you choose a green day, you can have unlimited pasta, rice and potatoes.
Fruit, vegetables and eggs are unlimited regardless of what day you're on.
Secondly, you choose 3-4 'healthy extras' a day. There's a large choice but they include 1/2 pint of milk, a couple of slices of brown bread, a lump of cheese or some pasta, meat fish etc (you only use these as healthy extras if you're on the 'wrong' day to the eat them).
Thirdly, you have 5-15 'syns' per day. These are items such as butter, ketchup, alcohol, chocolate, crisps etc.
I like red days and today I ate:
Breakfast: Sausage (low/no fat), Bacon, mushrooms, tomatoes, eggs, baked beans. Fruit
Snack: Yoghurt and fruit
Lunch: Tuna Salad
Snack: Sardines (I know I'm strange but I love them!)
Dinner: Chicken breast with ham and cheese, small potato, roasted veg
Snack: Packet of crisps
Drink: two glasses of red wine.
So in the above day, my breakfast was pretty much free (maybe a syn or two for my sausages!) and I used baked beans as a healthy extra. My yoghurt and fruit are free.
My tuna salad is free, although I sometimes have some salad cream for 1-2 syns. I used another small potato as a healthy extra, and some cheese in my dinner. The rest is free. My crisps are 5 syns or so. And my wine.
I also save a few syns so I can have a drink at the weekend.
Long term eating sustaining weight loss is achieved by increasing healthy extras, not syns.
It's a good diet. It works for me because I can't not eat and just milkshakes all day. I also wouldn't like weight watchers because you count *everything*... even fruit! And if you do their no count thing... you have to stick to three meals a day... which I wouldn't like as I'm a 'snacker'.
It's also a good alternative for those coming off VLCDs I think, because you can do a low carb version of a red day for a week or so to slowly get you out of ketosis. I'm sure slimming world wouldn't recommend that, but a woman I know did it and it worked well for her.