Some people with liver disease must eat a special diet. This diet helps the liver function and protects it from working too hard. Proteins normally help the body repair tissue. They also prevent fatty buildup and damage to the liver cells.
Advise is a verb, and advice is a noun. So advice is what is given, while the act of giving advice is called advising (or to advise).
To advise someone is to give them advice, or counsel. If you live in Iceland and a friend visiting you from Hawaii asks what he should pack, advise him to bring warm clothes and snow boots. Advise comes from a Latin word for vision. We want people to advise us if we think they can see the whole picture better than we can. For this reason, we often seek the advice of trained people. Financial advisors advise their clients on which funds to invest in. Legal advisors advise their clients on the law.