PRINCESS DIANA MAY NOT YET BE READY TO confess publicly to problems with bulimia, but plenty of other celebrities have. They include:

Jane Fonda, 54, who says she was bulimic from ages 12 to 35: ''I would literally empty a refrigerator. I spent most of every day either thinking about food, shopping for food -- or bingeing and purging.''

Judy Collins, 53, became bulimic after giving up smoking in the 1970s: ''I went straight from the cigarettes into an eating disorder. I started throwing up. I didn't know anything about bulimia, certainly not that it is an addiction or that it would get worse. My feelings about myself, even though I had been able to give up smoking and lose 20 lbs., were of increasing despair.''

Elton John, 45, was bulimic from 1984 to 1990: ''I'd gorge myself, then deliberately make myself sick. For breakfast I'd have an enormous fry-up, followed by 20 pots of cockles ((shellfish)) and then a tub of Haagen-Dazs vanilla. . . . If I was eating a curry, I couldn't wait to throw it up so that I could have the next one.''

Ally Sheedy, 30, spent her later teenage years as a bulimic: ''You have to be willing to change that sort of behavior, and it took me years to beat it. When you have an emotional disorder, you have to decide that you don't want your life being ruled by an obsession. And food is an obsession, whether you're gorging ((on)) it or refusing it.''

Joan Rivers, 59, suffered from bulimia after her husband, Edgar Rosenberg, committed suicide in 1987: ''Every part of my life, no matter how minor, overwhelmed me. I was nibbling all day long -- chocolates, pasta, cookies. But I cleverly figured out a solution to the overeating. I went into the bathroom, put my finger with its pretty little $4.50 nail down my throat and threw | everything up. . . . One day I found myself in a public toilet vomiting my head off. Dear God, I thought, I'm in trouble.''

Lynn Redgrave, 49, a recovered bulimic who was until recently the national spokesperson for Weight Watchers: ''((Bingeing and purging)) felt like a great discovery, as I suppose it is to most people. People complimented me on my weight, but inside I felt like s--t.''

Carling Bassett, 24, who suffered from bulimia while on the pro tennis tour: ''It becomes part of your life, like smoking. Or it's like being an alcoholic. It's so easy to get into and so hard to get out of. I hated myself that I couldn't stop.''

Cathy Rigby, 39, the Olympic gymnast turned actress, who was bulimic for 12 years from the time she was 16: ''I wanted to be perfect in my attitude and in my weight. Inside I was going crazy. I probably consumed 10,000 calories a day or more in fast foods. I can tell you where every McDonald's and Jack in the Box was along the way ((to my voice lessons)) -- and every bathroom where I could get rid of the food.''