Juice fasting, also known as juice cleansing, is a detox diet. During this diet, you are only allowed to consume fruit and vegetable juices, but you should make sure to get enough nutrients from them. It is important to drink more vegetable juices, since fruit juices have high sugar content.
This is maybe the safest way to lose weight, but important thing is that it’s beneficial for the entire body, and it will give your digestive system a rest.