I used to say the same as you Rich. Eat less, move more! But when your on your feet all day long, you want to come home and relax put ya feet up and watch telly etc....not spend hours down the gym then come home and eat a salad, only to find at the end of the week that you have only lost 1/2 a pound

then go out at wekend and put on 2 pound

This happens to a LOT with people. So what do they do? Say sod it...as it takes so long and isn't rewarding. Yes some people do lose on other diets and excersing, but everyone is different. I recommend that people who have been there and done it with all the diets and excersising do this diet, get it over and done with in months
As Mark says, a 2 hour therapy class is also in the cost. These go through the diet and why people put on weight, talk about how you feel etc but most of all put you in the right frame of mind for when you start to eat again! And also give you many different ways in which to cook food I.E a sunday roast is around 1800 calories cooked the traditional way but the same food can be cooked different to be around 800 calories....