Kirsch says you can "expect to lose up to 14 pounds, five inches off your waist, and a heavy percentage of body fat during the first two weeks of the plan alone".

According to Kirsch there is something very "New York" about wanting to change your life in just two weeks. Of course he also carefully points out that this is a plan for life.

Nutritionally the plan takes a low-carb high-protein approach.

Phase 1
Two weeks long. Don't eat: alcohol, bread, starchy carbs, dairy, coffee, extra sweets, fruit and most fats. Do eat, nuts, chicken breast, mushrooms, egg whites, salmon, low-starch vegetables, and lots of whey protein. Daily Calories: 800-1,000.

Phase 2
Two weeks long. Similar to phase 1 but with the addition of one extra daily carbohydrate serving (e.g. beans, sweet potatoes, berries, apples).
Calories: 900-1,000

Phase 3 (the "lifelong" phase)
Some of the "forbidden" foods in Phase 1 can be introduced in moderation.

Pros
 

• The book has a lot of material, including recipes, and a well-written and comprehensive section on exercise. A number of workouts have been described including pictures and diagrams - using mostly body weight, a medicine ball, and a large exercise ball.
• There is a useful section on "How to eat out" describing options for many popular restaurants.
• The book has a bibliography that lists references backing up some of the claims mentioned earlier on (this is rare in a diet book).

Cons
 

• This a very restrictive diet, that, in my opinion, heavily enforces the "dieting mentality" - a negative mindset that I personally discourage.
• Calorie recommendations are very low.
• What's the rush? The addiction to instant gratification never seems to lead to lasting results or happiness.
• The book is heavily endorsed by model Heidi Klum - there is a even a two-page section ("Real-life Transformation") that outlines Heidi's great experiences with the diet. I suspect that many of us simply can't or won't identify with a professional model - someone whose career rests on controlling their weight. This was a real turn-off.
• Meal replacement shakes make up a big part of the meal plans. These are wonderfully useful as a convenience food - but not as a staple.
• Ironically - the Ultimate New York Diet adheres to the "How to Write a Diet Book" post here at diet-blog - it includes at least 5 of the 10 promises.

Conclusion
I have no doubt that the Ultimate New York Plan will cause weight loss, and in many cases it may well be rapid in the initial weeks. However the obsession with quick-fixes and restrictive diets is something I am not a fan of - and therefore would not feel comfortable recommending this book.