Dr Fiona McCullough, Division of Nutritional Biochemistry, University of Nottingham, replies: In a situation of total lack of fluid, to drink one's urine will help keep the body hydrated. The waste products that the kidneys detoxified first time around will be detoxified again. The body may be able to reuse small amounts of nutrients, but this will not significantly contribute to a person's overall fluid intake.

The Chinese, among others, have engaged with this practice in the past and there is some anecdotal evidence of it being successful as a beauty aid and even reducing the risk of some diseases. I must point out this has not been scientifically proven using controlled trials. In general, I would not encourage you to drink your urine. It's better to engage in a healthy lifestyle.