Amanda Knox cannot sleep or eat properly as she awaits to know if an appeals court in Italy will uphold or overturn her murder conviction, according to a friend of the jailed American student .

A verdict is expected in early next month, capping an appeals trial that began almost a year ago.

Ms Knox was convicted of sexually assaulting and murdering Meredith Kercher, her British roommate in Perugia, and sentenced to 26 years in prison. Knox’s boyfriend at the time of the 2007 murder, Raffaele Sollecito of Italy, was convicted of the same charges and sentenced to 25 years.

They deny wrongdoing and have appealed their convictions, issued by a lower court in 2009.

Madison Paxton, a friend from the University of Washington who has moved to Perugia to be close to Knox and visits her in prison regularly, said that Knox has no energy and tires very easily. “In these days coming towards the end, finding very peaceful moments is hard for her,” Ms Paxton said. “Her sleep is very disturbed, her eating is very disturbed.”

Ms Knox, 24, has visibly lost weight and appears worn out by four years behind bars. Her lawyers and family have described her as increasingly anxious as she awaits a verdict.

These week, defence teams will sum up their case. Ms Knox herself is expected to address the court in a final plea. In a letter sent to Italian lawmaker Rocco Girlanda, who has campaigned for her freedom and frequently seen her in prison, Ms Knox said she has been thinking about what to say to the court and what to do if she is released. The letter, dated August 9, was shown on an Italian TV show on Sunday night.