Saturday was the day that Sandra Dee loved the most. After a week of make-up, couture clothes and film sets, the pretty 14-year-old would lock her bedroom door, read magazines and indulge in her favourite treat: walnuts. Her famously overprotective mother, Mary, was used to her daughter's solitude, so she wasn't too concerned on one such day when the teenager still hadn't emerged by late afternoon. However, as darkness fell, Mary thought she'd better check on her.

She called through the bedroom door, but there was no answer. Worried now that she hadn't seen or heard from her daughter for 12 hours, Mary forced the door open. On the floor, she discovered the girl's motionless body; her huge brown eyes were open but glassy and seemingly lifeless.

Shortly afterwards, emergency doctors at UCLA hospital pumped out the contents of the young star's stomach and saved her life. At first, they thought she had attempted suicide over a boyfriend, but a blood test established something more sinister. Her near-death experience was caused by dangerously low levels of potassium - the result of anorexia and bulimia. It turned out that the teenager was regularly bingeing on Epsom salts, using them as a laxative to purge herself of food.

Her adoring public had no idea that screen idol Sandra Dee had suffered from eating disorders since she was nine - or that her home life was a mix of bizarre rituals and even abuse. Instead, she projected such innocence and virtue that she became the poster girl for goodness in the pre-sexual liberation climate of the 1950s and early '60s.

In the hit movie musical Grease, set in that era, the character of Rizzo famously sings, "Look at me, I'm Sandra Dee, lousy with virginity" - but these taunting lyrics could not have been further from the tragic truth of the star's life outside her film career.

Sandra Dee was born Alexandra Zuck on April 23, 1944, in America's New Jersey, to Russian immigrant parents who divorced when she was five years old. The little girl had always been tall and well developed for her age and, driven by poverty, Mary forged her birth certificate to increase the child's age by two years so she could start school and her mother could work.

After Mary's swift remarriage to real estate developer Eugene (Gene) Douvan, young Sandra became estranged from her real father, later recalling one bizarre incident that occurred when she was 11. Boarding a bus with her daughter, Mary suddenly pointed to the driver and said, "Look, that's your father. "

Mary's mothering style bordered on obsessive. She breastfed her daughter until she was two years old, only stopping after she was advised that her milk alone wasn't sufficient for a toddler. She then began a strange practice, spoon-feeding the child until she was six. Everything was served from a giant bowl - either oatmeal with raw egg, or a full cooked dinner mashed into soup. It hardly seems surprising that the young star developed a dysfunctional relationship with food that would last her a lifetime.

Mary also dressed her daughter - "like a doll" was one aunt's observation - in velvet dresses and frilly skirts. "She loved to spend the day curling my hair, " said an adult Dee, who recalled one occasion when her mother stood gazing at her through the window of the school door until her teacher finally pulled a curtain across it to make her go away.

The birth certificate forgery soon had another advantage. After her daughter was spotted at a Girl Scouts fashion show, Mary propelled her into modelling work. Her career took off and, by the time she was 11, she was reputedly earning $US75,000 a year, appearing in national glossy magazines. This led to TV commercials, then a meeting with film producer Ross Hunter who, enchanted by the "14"-year-old before him, recruited her.

Hollywood success came quickly. With the new name of Sandra Dee, she debuted in Until They Sail in 1957 and, within two years, had starred in five hit films. Signed to Universal, Dee found that her childhood had officially ended - and a life of isolation had begun. In between filming, the teenage star sat for up to four hours a day alone in a classroom at Universal, busy with schoolwork.

"I never considered myself a child, " she once insisted. "I never remember playing with dolls. When the alarm went off at 7am, I'd dress myself, order a cab and go to work. I never had any friends, but it's like strawberry shortcake. If you've never had it, how can you miss it? "

Actress Debbie Reynolds, whose title role in the Tammy series of teen movies Dee took over and made her own, described her as the "cutest thing in the whole world". But Dee was riddled with self-hate, believing that she had fat cheeks and yearning for the elfin looks of actress Audrey Hepburn.

Between 1960 and 1964, Sandra Dee was one of the top 10 film stars in the US after the successes of The Reluctant Debutante, Gidget, A Summer Place, the Tammy series and Come September. But before her film career even began, she was already an experienced anorexic.

Concerned by her rail-thin physique, make-up artists would try to bribe the young star by offering to give her lipstick if she'd drink a malted milk, but their pleas were to no avail. In fact, while on set filming her first picture, Dee became so bloated as a result of her "lettuce diet" that her pants split. "I looked like an elephant from the waist down" is how she later described it. She was diagnosed with acute oedema - the tiny star was so malnourished from lack of protein that her renal system shut down and she was unable to urinate, causing the shocking bloating.

But while her eating disorder was physically evident from the start of her film career, the sexual abuse that Sandra Dee had suffered from the age of five was better disguised.

John Saxon, Dee's co-star in the 1958 film The Restless Years, said she'd often make cryptic remarks about her stepfather. "Every once in a while, Sandra would say something seemingly out of context that I didn't understand, " he recalled. "For example, 'I hated my stepfather so much, I couldn't even go to his funeral. ' I didn't know exactly where that was coming from until many, many years later. "

"Gene didn't molest me only in the mornings, but during the day, the night, whenever he wanted to and there was an opportunity, " Dee revealed in a 1991 interview. "He'd say, 'Let's snuggle', and I never fought back - I was too small. Too young. " The abuse finally ended just before Gene died, when Dee was 12 and on the verge of stardom.

Dee always believed that her mother had known what was going on but refused to acknowledge it. Every morning, Mary sent her daughter to say goodbye to her stepfather in the couple's bedroom. On her return, Dee would ask her mother to button up her open blouse in a silent plea for help.

She was so adept at hiding her pain that when crooner Bobby Darin met her in Italy, on the set of the 1961 hit Come September, he thought she'd never even been kissed. Entranced as soon as he saw her sailing into port on a yacht, Darin proposed. Showing her quick wit, Dee replied, "Not today. "

The sophisticated Darin was eight years her senior and at first she found him over-bearing, saying later that she "didn't want anything to do with him". Darin wasn't used to rejection, and the challenge made Dee all the more attractive to him. He continued to propose to her every day until, on her mother's orders to "be nice", she accepted his invitation of a carriage ride through the streets of Rome. By the next morning, she was in love and, against her mother's wishes, married Darin just two months later, aged 16. The wedding took place in secret at dawn, and the bride went barefoot.

On their wedding night, Dee was so paralysed with fear that she slept on the couch. But she eventually lost her dread of sex. "I thought I had never felt so safe in my life as I did with Bobby, " she later revealed.

The marriage looked set to help Dee find the happiness, security and contentment she had craved all her life. For a while, she and Darin were one of the most admired couples in Hollywood, cementing their status as celebrity royalty by starring together in two more hit movies, If A Man Answers (1962) and That Funny Feeling (1965).

But sadly, things soon turned awry. Darin, told that he would die young from a heart condition he'd had since childhood, was obsessed with living life to the full; Dee was a movie star but had never really lived. Jealous of Dee's idol status, Darin travelled restlessly with his band, mercilessly hustling for movie roles in a quest for fame, fortune and critical acclaim as an actor.

Bored, lonely and ill at ease with her husband's entourage, Dee began to seek consolation in drinking and gambling, later confessing that she was addicted from her first drink. "My God, there should be a law against martinis, " she observed. "I had my first one and I didn't think it did anything, so when somebody said, 'How about another? ' I said, 'Sure! ' And wow, I got looped. "

Despite several miscarriages due to her anorexia, Dee gave birth to a son, Dodd, in 1961 and hoped that motherhood would promise a new start to her troubled marriage. For a while, she prided herself on taking care of her baby, but after a nanny was employed so she could again watch Darin perform in casinos, the martinis proved irresistible.

Drunk and angry, Dee turned against Darin. Socially inept away from any type of environment that wasn't a film set, fuelled by alcohol and unbalanced by anorexia, she lashed out at her husband and his band to gain attention. Her favourite stunts were to pull out of social plans embarrassingly late, or demand they leave a club she'd wanted to go to as soon as they arrived. Asked once why she behaved the way she did, Dee bluntly replied that it was because she wanted "to stir things up". In truth, the child star was longing for someone to tell her to grow up; Darin eventually did - by divorcing her in 1967.

A mother and divorcee at just 23, Dee blamed herself for the breakdown of her and Darin's relationship, telling friend and former assistant Natalie Stortz, "My tantrums drove him away. " Unable to replace her first and only love, she would never remarry.

The teen idol was finally coming of age. "I'm a big girl now, " she once said. "If I want to, I can say hell and damn and maybe even something more zingy. " But her star began to fade, and although she tried more adult roles in films such as The Dunwich Horror (1970), no-one wanted to see a grown-up Sandra Dee. She soon realised that she was never going to regain her former glory, admitting, "All the movies I've been offered have been a disaster. Nobody knows how difficult it is to lose the ingenue image. " Eventually, the film offers tailed off altogether.

Just as he'd feared, Bobby Darin died prematurely in 1973 following a series of heart operations. It was a tough time for Dee. Her money
dwindled and, due to a combination of extravagance, lack of work and bad investments, she ended up almost penniless, dependent on her mother again. By the time Mary died in 1987, Dee was a lonely, frightened alcoholic wretch who had little company apart from that of her devoted son.

"When my mother died, I died too, " she explained. "I couldn't function. I didn't go outside for nearly four months. I subsisted on soup, crackers and Scotch. "

Gradually, after hospitalisation and therapy, and with son Dodd's emotional and financial support, Dee recovered from her grief, but she had many relapses of alcoholism over the years. She enjoyed a brief return to glory in the acclaimed 1991 stage production Love Letters with old co-star John Saxon. But it was her frank account of her life in Dodd's 1994 book, Dream Lovers: The Magnificent Shattered Lives Of Bobby Darin And Sandra Dee, that gave her dignity in later years.

She also gained great pleasure from last year's film Beyond The Sea, starring Kate Bosworth as Sandra Dee and Kevin Spacey as Bobby Darin. Before the film's release, Dee asked Spacey for a private screening, after which, overcome with joy and gratitude, she phoned the actor and thanked him, saying, "I don't want to change a frame. " It was one of her final moments of happiness.

In the months leading up to her death, at age 60 on February 20, 2005, Dee was on kidney dialysis three times a week. Smoking too much and eating too little, she was investigating transplant options, but her long-standing complications were too great.

Trying to come to terms with Dee's struggles, Dodd wrote: "I wonder what my mother's life would have been like if she hadn't been so pretty. If she hadn't been so attractive to a dirty old man. If her mother hadn't been so mesmerised by her beauty that she turned her into a doll. If Sandy hadn't had those melting brown eyes that told a Hollywood studio they were looking at a movie star... Bad things happened to little Sandra Dee."