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).
verb (used with object), advised, advising. 1. to give counsel to; offer an opinion or suggestion as worth following: I advise you to be cautious. 2. to recommend as desirable, wise, prudent, etc.: He advised secrecy for the sake of national security. 3. to give (a person, group, etc.) information or notice (often followed by of):