Beat ways to communicate the need for salt-free food

One of our friends that will be traveling to Italy with us next year can not tolerate any salt in his diet. He suffers extreme swelling if he eats any salt. What is the best way for him to communicate his salt intolerance to waiters and the people that prepare the meals? What is the best way for him to communicate his desire to have the waiter ask the person preparing the food to recommend dishes that can be prepared without any salt before he places his order?

you could try Si può dire al cuoco che non devo avere il sale nel mio cibo per favore

Ciao Jim, if your friend would like to tell the waiter about it, he should say ... "io sono allergico al sale. Puo' chiedere al cuoco se puo' consigliarmi un piatto che non contiene sale per favore"? (I'm allergic to salt. Could you please ask the chef if he can suggest a dish which doesn't have any salt?"). I hope this helps. Ciao