Heralded by the New York Times as "perhaps the most comprehensive approach to eating for effective weight control," the Instinct Diet has garnered popular reviews from media and dieters alike. So what is it, exactly? What is the science behind Susan Roberts' book, and how does it translate, practically, into weight loss results?

Blog posts and Amazon.com reviews alike are overwhelmingly positive, when it comes to the effectiveness of the Instinct Diet in a dieter's quest to lose weight. But why does it work?

The Instinct Diet is based on nutritional science (in which author Susan B. Roberts holds a PhD), but also takes into account human hard-wiring around the issues of food and eating. It advocates not only eating less calories and more traditionally "healthy" foods, but working with our bodies and minds to be more concious of why we overeat in the first place. As anyone familiar with 12-step programs will tell you, awareness of the problem is the first step to change.

Dr. Roberts suggests 5 key reasons people eat too much:

1. Hunger - We eat because we need to satisfy our hunger.
2. Availability - We eat because it's there.
3. Calorie Density - Higher-calorie foods taste good.
4. Familiarity - We like foods we are used to.
5. Variety - We like to eat a range of different things.

Instead of fighting these instincts by limiting ourselves to a certain set of pre-prescribed foods (like on low-carb or low-fat diets), Roberts suggests working with them. Eating regularly, and eating a variety of foods, helps you feel satisfied, even as you reduce your overall caloric intake. This makes the diet easier to stick to, and the habits you create while on the plan easier to sustain, even after the initial weight is lost.

While most reviews of the Instinct Diet highly recommend it, it is not a magic bullet for weight loss.

Those following the plan report that they feel little or no hunger on this diet, which is a major factor for anyone choosing a weight loss plan.  It's also flexible, in that you can cook from the recipes in the book, modify your own favorite dishes, or eat mostly pre-packaged foods.  Some of the recipes will of course be more to one person's taste than another, so it is all about finding what works for you and your household.  Some complain that the higher-fiber recipes such as the "I-Bread" and the pizza base are difficult to stomach at first, but may grow on you as that familiarity instinct takes over.

High-fat foods are limited, but not excluded, so you do not feel deprived.  Dipping fruit in chocolate instead of chowing down on a giant slice of mud pie and using oil on your salads to make getting your greens more appealing are just two of the helpful tricks included in the book to maximize taste without maxing out your calorie budget.

Of course, the sustainable weight loss results are what speak most highly of this diet.  People in search of overnight miracles will not find what they are looking for in The Instinct Diet (or, indeed, anywhere), but for someone committed to changing their lifestyle and working with both body and mind to create a healthier future, this book is well worth the read.