The products will all work if the person is in a good weight range. There are no magic bullets. If you do what I recommend you will get the best results.
I am also a Registered Dietitian, Dietitian Assistant and a registered dietitian. My focus is on the medical side of this. My patients have had many years of success. If you don't have the time, or don't know what you want, you can email me. I am an easy to communicate and very informative person. The main difference between this diet and some other diets is the use of "calories in" and "calories out." If you do the math, your energy expenditure will be higher on this diet. You can use the calories in calculator to figure how many calories will be in your food. The diet is designed to get you into ketosis - a state of total metabolic rate that is below 90% of your resting metabolic rate. It will keep you in ketosis until you have maintained this state for one hour (or until you stop using it). You will not want to put too much on your plate at one time. You may not like the taste of a particular food, so you will want to make sure you don't overeat in the first days or weeks.