Abdul, who announced she was anorexic in 1995 and overcame the illness through counselling, is keen to help Mary-Kate, who is currently in rehabilitation in Utah.
And the American Idol judge urges fans of the Olsen Twins to write and offer their support - because eating disorder sufferers need to know they're loved.
Abdul says, "I was very concerned for her because I saw pictures. I actually sent a letter, just a note, saying, 'If you ever need anyone to talk to...' I don't know if she ever got it.
"I was really happy (she checked into rehab); I was proud of her. One of the proudest moments of my life was coming through that. It was a very triumphant moment.
"It's one of the most difficult things to overcome. It's something that's very shame based.
"It's not about food, it's not about what you eat, what you don't eat; it's about feelings and how you manifest that and it's about shoving feelings down and thinking that you're not in control by not eating or by over-eating and about not knowing who to talk to.
"The most important thing is anyone who's a fan of hers or cares for her (should) write her letters. Lots of love and support really helps."07/07/2004 20:51