Hi R4j!
I'm on Slimming World. I've found that it can take quite a bit of time cooking the Slimming World way. So, I've found that the best thing to do is I spend a few hours twice a week or so making up big batches of food (spaghetti bolognese, chilli con carne, lamb rogan josh, etc) and then freezing it in foil containers.
This way I only have to cook a few times a week and can just pop the frozen meals in the oven for half hour when I need them during the rest of the week.
It's a really good idea to get some recipe books from the Slimming World class when you go so that you have a good idea of what you can cook and eat whilst on the diet.
Hope your weight loss goes well!
Good luck!