Just to start out, the diet plan consists of about 900-1000 calories daily. Some days it goes a little higher, probably trying to keep your body out of starvation mode. I definitely wouldn't recommend this book because of the low calories. It also is a low carb diet, so initally you will see some weight drop off, but just remember it is water loss. I don't like following low carb diets because as soon as I add in carbs, of course the weight comes back. (Carbs hold water- but no matter what, I don't like seeing numbers go down and come back up)If someone has quite a bit of weight to lose, don't buy this books. Because it is so extreme, people tend to lose motivation and feel too deprived. I am pretty lean myself, and I did not enjoy trying to follow this plan. Stick to a diet more balanced with healthy carbs, protein, and fats for a lifelong plan.