There are diets that can help in important situations where you need to lose some weight you have in that time. One of them, you will lose about 4-5 kilos at that time, 10 day diet, a diet that helps cleanse the body (like a whey-based diet).
The diet is as follows: The first day you just have to pick fruit, nothing else, the fruit you want but always fruit. The second day you leave the fruit aside because you can eat throughout the day are vegetables , which again anytime, but only vegetables.
Day 3 will be to consume only milk while on 4, 5 and 6 are meant to eat fish or chicken is a way to nourish yourself after three days without eating anything. On days 7 and 8 you can do is to eat meat, poultry or fish, in this case, expanding the type of meat.
The last two days is to eat brown rice or lentils. Those would be the last meal.
In all these days the water is a must because that is how you will have to hydrate. If you drink more than 2 liters would be fine but if not, 2 liters is necessary.
Diet has a difficulty to be many days with the same type of food a day (which makes you get bored or do not know what to eat).