We're not big believers in long-term fasting. But if you want to try a one-day mono/mini-fast (and you have no health problems and are not diabetic), why not try eating a single fruit, vegetable or brown rice for all day. Consuming one type of food keeps the pressure off the digestive system and allows the body to rest and cleanse itself. To make the single food more appealing, try juicing, eating it raw, poaching or baking. And veer towards vegetables rather than fruits, which are high in natural sugars.