to lose about 8 pounds a month (4kg roughly) I did slimming world, which is healthy eating, mainly low Glycemic Load /Low GI, with loads of fresh vegetables and protein and fairly low carbs.
to lose 12 pounds a month (6kg very roughly) I'm doing Lighter life, which is pre-designed food packs with about 100 grams of carbs per day in total. I also take psyllium husk just for added fibre, and lots of fresh water and a hot broth which is like hot watery vegetable soup.