While, yes, detox refers to substance abuse treatments, it's also a way to cleanse the body of toxins from your diet. Oftentimes, detox diets are done in short doses, from a matter of days to a couple of weeks, and used to purify the body and strengthen the liver, which is used for detoxification. Last year, Roni DeLuz and James Hester (both pictured) wrote the book "21 Pounds in 21 Days: The Martha's Vineyard Diet Detox."