There is an old saying that "imitation is the most sincere form of flattery". On that basis the Negative Calorie Diet scores well. Numerous copy-cat diets and books have subsequently been released since this original work was produced.

The Negative Calorie Diet was originally written by a US Navy 'PRTC' (Physical Readiness Training Coordinator). It was in that role that the diet was originally researched. It became widely used by the US Army, Marines and Navy to get their new recruits into shape.

The theory behind this health-energy-fitness oriented diet is very interesting indeed. The research found that some foods require more energy consumption (ie calorie burning) by the human digestive system than the foods themselves actually contain.

The Negative Calorie Diet is a sound, healthy, balanced diet across the food groups. Nothing outlandishly faddish about it at all. It is scientifically reasoned, and proven effective by many thousands of people in the Armed Forces and in the general community.

Admittedly, this diet has its critics. (Don't they all?) Some nutritionists and dietitians argue against the basic premise of this diet - that some foods require more calories to digest than they actually contain. The critics argue that no foods meet such a criteria.

It seems, though, that the argument is not about whether the diet itself actually works or whether it is healthy or sustainable - just about the specifics of the scientific claims.

As various concepts such as the "glycemic index" are accepted by most nutritionists and dietitians, it is only a small step between the basic concept of the glycemic index (some foods are rapidly converted to blood glucose, others are very slowly converted) and the general thrust of The Negative Calorie Diet.

Given that it is accepted by nutritionists and human biologists that approximately 10% of our calorie consumption is from the digestive process itself, it is a small step to accept that some foods (such as sugars and starches) require less digestive time and effort and accordingly fewer calories to digest, while others such as proteins and the more complex vegetable carbohydrates require greater digestive time and effort - and more caloric burning to digest. After all, the accepted 10% figure is merely an average.

Maybe there is a case to argue against the "precision" of the claims of negative calorie foods - but not the general direction.

The Negative Calorie Diet, true to its origins as a "conditioner" for US Military recruits, is about much more than just food. It covers exercise and oxygenating breathing techniques beneficial to the fitness and weight loss process.

Like most other commercially promoted diets, however, it falls short in giving recognition to psychological and emotional issues involved in weight and obesity disorders.

Although The Negative Calorie Diet is promoted as a "stand alone" diet, I believe it also serves two other very important purposes:

1. Educational value about nutrition, the digestive processes and caloric values;
2. As a guide to be used in conjunction with other diet programs where flexibility and choice of menus are permitted.

Of course, there is no "perfect" obesity or weight management diet plan.

The question that must be answered is whether The Negative Calorie Diet is a lifestyle and behavior modifying program with proven effective results for most people, sustainable in the long run, and with significant health benefits compared to "normal" or "average" western diets.

The answer is "YES".