Unlike the other two reviewers, I really like this book and it's one of my many diet manuals (i've got hundreds!) that i find myself coming back to time and time again.
The authors don't tell you to count calories (as someone said below), more just be aware of them e.g. make sure you're not eating thousands of calories in snacks alone.
It is very much written in a 'do this', 'don't do that' format, but I find this breaks everything up and makes the book easier to read. I also love the humorous writing style, which is what attracted me to it in the first place.
The writers give lots of meal ideas, and really focus on telling you how to make 'boring diet food' like porridge and salads taste delicious. There's also lots of advice on things like: what to eat when you're out and about, how to deal with the midnight munchies, what the best options are alcohol-wise and how to cope when you're PMS-ing. Plus they also focus on diet-boosting foods such as fennel and linseeds, which you may not have tried before.
The whole vibe of the book is really about wanting to make the reader feel like they are a 'hot chick' regardless of whether they're at their ideal weight or not, which in turn should make you want to eat better and take care of yourself... then hopefully the weight loss will follow. After all, a healthy eating plan needs to be for life, not just for the short-term!