When I was on it a few years ago, I noticed a lot after 3 weeks. I suppose it depends on each person. I have a lot to lose so not expecting it to show for a couple of months. Lol
I've just started week 6 and I can get both of my hands into all my size 14 work trousers with ease now whereas they were tight fitted before, in fact one pair feels like they're going to fall down any time! Might be time to buy some size 12s I think!
I'm only on day 11 and I can feel the weight melting off me, I can tell loads on my face and my waist think I've lost just over a stone and had lost 7lbs the week before on slimming world so think this is why I can tell so much