Specific detox diets vary — but typically a period of fasting is followed by a strict diet of raw vegetables, fruit and fruit juices, and water. In addition, some detox diets advocate using herbs and other supplements along with colon cleansing to empty the intestines. Many alternative medicine practitioners promote various types of detoxification such as detoxification diets. Scientists have described these as a "waste of time and money". Sense About Science, a UK-based charitable trust, determined that most such dietary "detox" claims lack any supporting evidence. In cases of kidney failure, the action of the kidneys is mimicked by dialysis; kidney and liver transplants are also used.