I bought this book nearly three weeks ago and it really has changed my life! That might sound a bit corny but I've struggled to lose weight for years, now I know why. First off the book tells you how many calories you should be eating in a day for your weight/height etc, and how many to eat to lose weight. It then tells you to write everything down every day and add up all the calories, by looking up the food in the book. You immediately know if you have eaten too many calories, and what you actually do, if you want to lose weight, is eat less calories than your daily allowance. It's working for me, and is really making me think about what I eat. The best thing about it is there's no restriction on what you eat, and no things that you can't have - its up to you to eat a combination of food in a day to make the right number of calories.