The Coronation Street star, who plays landlady Stella Price in the soap, was given a wake-up call early in her acting career when she was snubbed for a fashion commercial because the casters thought she was taking drugs.
She told the Daily Mirror newspaper: 'I went to auditions for a fashion commercial and they said they didn't think I was quite right for it because I wasn't upmarket enough.
'Later that day my agent called to see if I was OK and told me that actually I had looked so awful the casters had thought I was a heroin addict and wanted to know if I was on drugs.
That was the wake up call she needed to sort out her illness and get her body back into a healthy shape.
The 50-year-old actress admitted she used alcohol as a replacement for food and opened up about how she had the 'body of a child'.
Michelle said that her lifestyle became a running joke amongst friends and family and they would joke about how she would only eat salad but still drink large amounts of alcohol.
Feeling full: Michelle, pictured right in 1998, used to drink alcohol instead of eating food
Although she knew she had the body of a child she continued to starve herself and then again binge eat, continuously stuck in the vicious cycle.
Michelle, who now works with charity b-eat, admitted she's scared for her 16-year-old daughter Maia because of the pressure to look a certain way.
Seeing 15 and 16-year-old girls posting photographs of themselves online in their underwear is something she hopes doesn't affect Maia.
Family matters: Michelle, pictured with daughter
Maia in 2012, is worried that the pressure to be thin is too much for
young girls