Just watched the RLS program on ch5. I had RLS for many years ( i'd estimate between 1991-2005 ). Felt a little like cramp in the back of my knee/hamstring, or like lemonade was bubbling below the surface of my calves, or ants crawling under my shins etc. Absolutely awful and i felt so helpless and frustrated. I (eventually) tried keeping a diet diary and a record of when it was good/bad and after a few weeks a clear pattern emerged: i'd get it soon after drinking drinks with sweetener in - particularly asparteme. I've since avoided all sweeteners and have had no RLS in 10 years. It's unlikely sweeteners are the root cause for everyone but it's worth trying.