When looking to cleanse your body, you'll find various types of detox food available. Potentially the most common detox food used are fruits and vegetables. Since these are very much in a natural state already, they will usually be the most beneficial for the body.
Other programs include an increased consumption of the detox food, fish and salmon. It is believed that the protein and essential fatty acids in these really help to clean the system and get the body functioning properly.
Juice fasts are also popular and are a good approach to use because they will provide more calories. When going on any type of fasting where you will be restricting your diet to a limited choice variety, you'll want to try and keep calorie consumption up to prevent a loss of lean muscle tissue. Obviously getting protein in would be better, however juice fasts can work over a couple of days relatively well without putting you at too much risk.
The other common choices that you'll come across on various plans are green leafy vegetables, lemons, watercress, garlic, green tea, broccoli sprouts, sesame seeds, cabbage and psyllium (a plant that's rich in soluble fibre). All of these have very healthy profiles and work towards keeping the body system functioning effectively.
Potentially a smarter plan however would be just including the above options in your every day diet so that you don't need to worry too much about cleansing your body in the first place since you'll already be very healthy.