You can lose 9 pounds in three days:
Day 1: Morning: half a grapefruit, 1 slice of toast, 2 spoonfuls of peanut butter, 1 cup of tea. Noon: half a canned tuna (preferably washed with mineral water), toast 1 slice, tea 1 cup. Evening: 2 slices of any lean meat, 10 beans (boiled in water).
The next day: in the morning: 1 piece of cheese (most of it), 2 pieces of soda crackers, 1 cup of tea. Noon: half a banana, 1 boiled egg, 1 slice of toast, 1 cup of tea. Evening: 2 hot dog sausages or children's sausages and half cauliflower (boiled in water)
Day 3: In the morning: 1 green apple, 1 cheese (most of them), 2 soda cookies, 1 cup of tea or coffee. Noon: 1 boiled eggs, 1 slice of toast, 1 cup of tea. Evening: Half of canned tuna (washed with mineral water.