Doctors have banned Demi Moore from weighing herself while in rehab.

The 49-year-old actress is undergoing treatment for "substance abuse and anorexia" at Cirque Lodge in Utah -- which has previously treated stars including Lindsay Lohan, Mary-Kate Olsen and Eva Mendes -- and medics at the centre don't want Demi focusing on her size while she recovers.

A source told RadarOnline: "It's common treatment practice at Cirque to not allow patients that are being treated for an eating disorder to see how much they weigh when they step on the scale. Their weights are taken everyday, sometimes several times a day to make sure that they aren't losing weight while in treatment. Doctors at Cirque don't want patients to fixate on their weight.

"Demi isn't being forced fed or chastised for not wanting to eat. The counsellors at Cirque are working on giving Demi a safe and controlled environment, she is getting the best care possible. She is also dealing with an addiction to prescription medication, and she has a comprehensive team taking care of her."

The actress is expected to spend at least 60 days in the treatment centre and will be prevented from contacting the outside world including her daughters Scout, 20, Tallulah, 16, and 23-year-old Rumer, former husband Bruce Willis or estranged spouse Ashton Kutcher, for some time.

The source added: "Demi won't be allowed to call anyone during the first week, nor can she receive any phone calls. As time goes by, and if Demi is doing well, her doctors will allow her to have limited access to her cell phone for a small amount of time."

Meanwhile, despite reports Charlie Sheen's former wife Brooke Mueller is attending the same facility for her own addictions, her representative told E! News she checked into a different "long-term inpatient treatment centre" in December 2011.