If you need to lose 2kg and get in shape for 3 days this is the right diet for you.  You will not feel hungry, because this diet uses groceries that will give you feeling of full stomach. The quantity of food is small so you may experience lack of vitamins and minerals. It is recommended to take supplements. You can also practice this diet after holydays to clean your body a little bit.
Note: this diet is not recommended to practice more than 72 hours.

Plan of a diet:                                            
Day 1
Breakfast: 1 slice of integral bread
1 cup of milk (regular fat)
Lunch: 300 gr of mashed potatoes
1 cup of tea without sugar (green tea)
Diner: 250 gr salad of boiled potatoes with 2 boiled eggs with olive oil
1 cup of tea without sugar (green tea)