Stephen, just reading the title "15 pounds/week" tells u immediately its pure "scam".
This given diet is "indirectly" saying: stop eating, starve yourself and if you do not die, faint or become a social aggressor from grumpiness, you would have lost weight.
Normally speaking you can never lose 15 lbs/week (which is a very unhealthy thing to start with and can cause serious damage).
With such diets, you will lose a lot of muscle (while the fat remains), your metabolism will become very slow, so your body will hold to each calorie you eat, and you will lose all healthy nutrients/minerals from your body, and your health will be affected.
When you want to lose weight, you have to understand 3 main facts:
- Extremely starving yourself will make you lose muscle, while fat remains. So, as soon as you stop your "bad" diet, you will eat twice what you used to eat before, and add new layers of fat on top of the ones you had = "you will gain fat"
- Losing fat is a process that requires time, all lose fat in a very short time diets are bogus and fake. In order to lose fat, you have first to adapt your mind to the fact that it is a process requiring time and effort (but can be done for sure), and healthy eating habits which you must make it a lifestyle. If you just think you can lose weight and then go back to bad quality food eating habits, you will re-start from zero and even more you will gain more weight and you will lose hope.
- You have to combine healthy eating (good quality foods with a variety to get all nutrient your body needs, and low calories) with exercise. You put yourself into a calorie deficit through these, but while giving your body all the nutrients it needs to stay alive and be able to spend your day full of energy.
There are several formulas to calculate your daily caloric needs (like the harris benedict equation).
Use this formula, eat good quality foods (whole wheat, oats, protein, fish oil, omega 3,etc.. do some research about them) and do some strength training along with some cardio (3-4 times a week).
So, let's say the formula gave you: 3000 calories per day. This is the amount of calories your body needs at rest (remember it might not be 100% accurate for you, you might need a bit less / more, you will see that through your progress). In order to lose 1 pound of fat per week, you need to have a deficit of 3500 calories per week => 500 calories deficit per day. So, you can have this deficit either by eating less than 3000 or by burning calories from exercise, or BOTH.
For example, say you eat 2900 calories per day => deficit 100 calories.
Then you burn 400 calories from exercise per day => deficit 400 calories
You now have a deficit of 500 calories per day , i.e. 3500 per week, so 1 pound of fat lost.
This is in general how it works. You will adjust your exercise level / eating habits through your progress to adapt to your accurate body genetics and requirements.
Never believe a notice that will tell you you will get ripped in a week, all weight loss routines require time, but at the end not only you would have lost weight but also you have now a habit of staying healthy, eating healthy and exercising to boost your energy!