Most of us find diets really exciting since they prove to be the fastest ways of knocking of our extra pounds. We get attracted to diets that claim they can help us lose 6 pounds or more in just a week. Do all of these diets actually work? Can we actually lose weight in just a week's time? And is that healthy? To answer your questions, not all diets are genuine. There are many diets that will claim to help you lose weight but some of them may not do that. Some of them are healthy and some of them are not. So you have to be careful about which diet you decide to follow. However diets that work along the lines of the calorie shifting principle are very genuine and effective. They do help you shed your extra pounds and in a way that is not harmful to your body. The most famous of calorie shifting diets is the "fat loss 4 idiots diet". This diet proves why other diets are most unhealthy and proves to you a good scientific method of losing your excess fat. Some of the most common diets work at reducing your calorie or food intake for an extended period of time. This helps you to begin losing weight. But more often than not, you start putting on weight even while still following the diet. The weight lost does not last long enough. This is because our bodies have been designed in such a way that if you give it a considerable amount of time, its metabolism adjusts to whatever your intake is be it less of carbohydrates, fats or proteins or just less intake of the quantity of food. The fat burnt is proportional to the rate of metabolism. If your metabolism is fast, you will burn calories fast too. If metabolism is slow, naturally the rate of burning calories will be slow too. Lesser the food intake, slower the metabolism. Most of these diets are all about taking in fewer calories and hence lesser calories are burnt up as well. And if you go out on a binge even on one day, you will land up putting on even more weight since your metabolism will be slow and you will not be able to burn much fat. The calorie shifting diets do not work like other diets. They have a scientific background. They understand that the rotation of eating routine is required in order to keep our metabolism high at all times. Higher the metabolism, more the calories burnt. The diet encourages the rotation of food stuff. It allows you to eat one type this week and to change it next week. So basically you eat new type of food every week. Your diet this week will not be the same as last week. This way your metabolism will be always high, thus burning out more and more calories.