Five days - easy:
No added salt to anything, no alcohol, chocolate, crisps or anything of a bombay mix / nibbles, 'just one more biscuit' type nature.
Meals for next five days:
Breakfast: Porridge with smidgen of cinnamon and chopped or grated apple, or natural yoghurt with raw oats in
Lunch: fish, salad leaves, herbs & oils / bean sprouts / wholemeal bread (proper health-foody or homemade ideally)
Supper: chicken with skin removed but herbs & garlic, new potatoes (not too much butter, but some) or bread again, grilled pork with fat cut off, herbs and garlic
Snacks: Natural yoghurt (not greek), Organix baby rice cakes in blueberry, blueberries / rasperries /strawberries in the fruit line, nuts
By the way, the lack of variation is deliberate - people tend to eat less over time when they have to eat the same thing frequently apparently.
Worked for me when I had to shed a few pounds in a hurry anyway...Best thing about it is it's seriously low effort to prepare - necessary when you're knackered and just want junk food.