In my experience different diets suit different people, as out metabolism varies from person to person. My friend and I went to a slimming class for a year, she got fed up and cheated quite often while I stuck rigidly to their diet and exercise - she lost a stone, I lost a few pounds. All she did was laugh and called it her choccy diet! I have tried many diets over the years and found the only way I can lose weight is to cut calories right down to about 800 per day.