This is from a 2011 Daily Mail article after her autobiography was published:
"...in the privacy of her New York studio flat, she'd mutate into a kind of primitive being, ravenously munching her way through barely imaginable quantities of food.
Afterwards, she'd make herself sick. 'The demands of bulimia,' she says, 'outshone the power of my desire for Woody. Pathetic, but true.'
Even now, at the age of 65, she can remember with a former addict's precision the content of the stupendous meals that she ate during her five years as a bulimic.
For breakfast each day, she'd shovel down a dozen buttered corn muffins, three fried eggs with bacon, pancakes and four glasses of chocolate milk. For lunch: three buttered steaks with charbroiled fat on the side, two-and-a-half baked potatoes with sour cream, apple pie and two chocolate sundaes with extra nuts.
Dinner almost defied belief: a bucket of Kentucky Fried Chicken, several orders of chips with blue cheese and ketchup, a couple of TV dinners, chocolate-covered almonds, a large bottle of 7Up, a pound of peanut brittle, M&Ms, mango juice, one Sara Lee pound cake, and three frozen banana-cream pies.
...eating and purging around 20,000 calories a day gave Diane heartburn, indigestion, irregular periods, low blood pressure and 26 cavities in her teeth. The psychological effects were arguably worse: she was using food to escape reality. Woody suspected nothing, though he often marvelled at her extraordinary appetite. Assuming she was just desperately insecure, he packed her off to a psychoanalyst, whom she saw daily for 18 months. Then, at 25, for no apparent reason, she suddenly began eating normally again."