Courtesy of Sigmund, Carl and Alfred comes an actual formula for the diet that the Royal Navy has been using. I am quoting it all here so I have it for future reference as well.
As a public service, SC&A will provide you with the last diet you'll ever use. We're serious. It is commonly used by members of the Royal Navy. The diet is comprised of two parts- diet and exercise, each dictated by certain factors.
Let's say you are a male, weighing 220 lbs, who wants to weigh 180 lbs.
Take the desired weight (in this case, 180), multiply by 10. That is the number of calories you can consume in a day. In this example, the caloric intake cannot exceed 1,800 calories.
That is the first part. Next comes the exercise part.
To calculate the required amount of exercise follows: Take your current weight and again, multiply by a factor of 10 -- in this case, 220 multiplied by 10 equals 2,200.
Each factor of 1000 means 1 hour of exercise. In this case, 2200 means 2.2 hours of moderate exercise, such as walking.
The preferred method would divide the exercise into 2 or more equal sessions.
Let's say you are woman, who weighs 175 lbs, and your desired weight it 130 lbs.
Multiply your desired weight (130) by 10 to yield the number of calories allowed per day -- 1,300.
Multiply your current weight (175) by 10, to yield the amount and time of exercise that must be expended -- in this case, 1,750, meaning 1.75 hours per day.
Remember, it is best if the exercise is divided into at least 2 times per day. For example, in the example, that means about 50 minutes of walking, twice a day.
We have seen the diet work and we have used it ourselves. We have seen in two instances, the loss of up to 60 lbs and 90 lbs respectively, in 90 days or less. Naturally, lesser amounts of weight have been lost in that time.
To be most effective, the amount of exercise should remain constant if you want to lose weight quickly. In other words, if you lose most of the weight, it is still best to do the same amount of exercise as you did when you started.