She ran from her home to her job stacking shelves at Franklins supermarket. She ran to the cemetery to see my grandmother. And she ran, every Monday morning, to our place in Matraville to drop off a packet of Arnott's biscuits and to watch 15 minutes of the Today show with me. I'd hear her creep in on those mornings, even more mouse-like than she usually was, at around 7.15am. It was my morning alarm. The screen door would squeal, light footsteps would patter through to the kitchen and, minutes later, the kettle would whistle. We'd sit in the rumpus room and talk - I'd tell her about school and she'd tell me about work and her dog, Skye. I'd have a biscuit - she never touched them - and try to listen.

But she was hard to talk to: she spoke softly and quickly, her airy words running at you in clauses, not sentences. And there wasn't much common ground. As a teenager, I dreaded those awkward mornings, wishing I could just shut my eyes and pretend I was asleep until I heard her slink back out to run home. And sometimes I did just that.

Eventually, Debbie stopped coming. She'd broken a bone in her foot, one of many fractures to come as osteoporosis burrowed through her body. She didn't give up running altogether; still hurtling herself to work as casts were removed and sometimes running with plaster locked onto her foot. But her body soon grew more stubborn than her mind, and a broken leg put her in a wheelchair. Not too long after that, I received a panicked call to say I had to get to hospital; Debbie had been rushed in with severe pneumonia.

We were there for hours, doctors coming in and out of the small family room to keep us updated.

My uncle translated the final update for the rest us: "Her organs just can't cope." In the early hours of the following morning, we filed into Debbie's room in pairs to say goodbye. I went in with my cousin, and when we peeled back the flimsy hospital curtain we found Debbie lying unconscious on her side, pressed down by a sheet, a mess of tubes curling into her body. She was tiny, almost like a newly found fossil half stuck in the ground. An oxygen machine fed her air and with each enormous, forced breath, she swelled like a balloon before deflating to almost nothing. I'd always known my aunty had anorexia. But that night was the first time I saw it up close.

Deborah sue salmon died on wednesday November 5, 2008, aged 49. Her yellowing death certificate lists her cause of death as pneumonia (which she had for "days") - friends still remember the thick, phlegmy cough - and notes the chronic illness that left her so vulnerable: anorexia nervosa (which she had for "years").

Almost since anorexia nervosa was given its name in 1873, it has been thought of as a disease of the young; in our world, it is the burden of models and starlets starving themselves pretty, and of those who want to follow in their paper-light footsteps. But while young women make up the majority of cases - 90 per cent of bulimia and anorexia cases occur in women, and the median age of onset is 17 - there has been an uptick in the number of older women presenting with the disease. Some of these are new sufferers, others are long-timers, like Debbie, who began starving herself in her teens and dipped in and out of this behaviour her whole life. Anorexia took a hold of these long-time sufferers in their youth, and like 30 to 40 per cent of those with the condition, they never fully recovered.

Just months before Debbie died, UK professor Rosemary Pope made news when she collapsed in her home, also aged 49, felled by a stomach infection after decades of living with anorexia. The Daily Mail reported that her heart had shrunk to the size of a child's. The following year, the BBC aired the controversial documentary series Desperately Hungry Housewives, which followed the lives of four middle-aged women with eating disorders.

Last year, University of North Carolina academic Cynthia Bulik released the book Midlife Eating Disorders: Your Journey to Recovery. In it, Bulik paints a grim picture of what decades of living with anorexia does to someone like Debbie. "If you don't give your body any food, it starts eating itself," she tells me. Muscles disintegrate, the heart shrinks, osteoporosis hollows the bones, skin shrivels and dries, hair and teeth fall out, and some people grow a downish, almost duck-like fur called lanugo on their face and back - the last cry for warmth from a body deprived of fat.

"It's a dangerous stereotype that anorexia nervosa only strikes young women," says Bulik. "I've had older women who have undergone exhaustive tests looking for some cause of their weight loss, but no one ever asked them the diagnostic questions for anorexia. I have had women whose doctors have said, 'You can't have the disease, it's only for kids.' "

In the days immediately after Debbie died, my cousin Kylie and my two older brothers cleaned out her small housing commission flat in South Coogee. There was hardly anything inside: two treadmills (one broken), a garbage bag full of socks, jar upon jar of peanut butter, cupboards full of barley sugars (sorted into sandwich bags so that each had the same number of lollies) and, though it was early November, wrapped Christmas presents for the entire family.

There was also a book, Biting Anorexia: A Firsthand Account of an Internal War, by Lucy Howard-Taylor. Somehow, it came into my hands and I've kept it - wrapped in bubble wrap - ever since. The book itself is Howard-Taylor's story: the Sydney girl was throttled by anorexia in her latter years of high school and early years of university and kept a diary of her experiences, later turning it into a book. It's a remarkable work, but Debbie's copy is unique, and not just because it still smells of stale cigarettes.

Debbie annotated the book as she read it - page after page of text is wildly underlined in dark blue ink and written thoughts are scrawled up the margins and into the corners. She wrote as messily as she ran: one annotation notes that "teachers told me I would fail the HSC because people couldn't read my handwriting (I didn't though)."

On one page, she underlines a passage that states, "I was very lonely. And I came to understand that there was something intrinsically wrong with me." She underlines another passage where Howard-Taylor writes: "I shrank from hugs. Especially from my family. Hugging them I would feel them feeling my spine ... So I stopped."

In the margins, Debbie writes about the foods she allows herself ("low-fat peanut butter measured limited quantity - love peanut butter") and the terror that would follow any binge: "Stages where you wake in fear that you might have binged and forgot how to lose the weight if you did." She confesses to sneaking hunks of ham to the dogs at family dinners, and to swallowing whole bottles of laxatives.

When the disease first took hold in Debbie's late teens, my grandmother Iris, Debbie's mother, fought it fiercely, at one stage having a court order issued to force Debbie into psychiatric care at Prince Henry hospital. Debbie writes into the blank spaces of Biting Anorexia, "Mum came into the room ... half dead on drip ... commanding me if I wanted to be her daughter [to] keep fighting." Later, she confesses that when her mother died, "My sick mind said now you don't have to eat, you can do what you've wanted to do."

Mum says everything changed for Debbie when the family moved from Charleston, West Virginia, to Sydney in 1969. My mother, Starlena, was 14 and Deborah was nine. Mum was excited about the beaches and the houses (she'd heard they were larger Down Under), but Debbie had been happy living where she was in the US. She was the prettiest of the three sisters, fending off little "boyfriends" at school.

The move was supposed to be a fresh start. Grandpa Jack Salmon took advantage of an assisted-passage scheme for ex-servicemen and loaded the family onto the African Crescent, a cargo ship whose hull they called home for the month's journey to Port Jackson. My grandfather was a drinker, and the hope was the big change might do the family some good. Things did not work out as planned. Arriving at Sydney Harbour on the kind of wet night they never put on postcards, the Salmons were bussed to a migrant hostel in Matraville where they would live for eight months. Flooding in the hallways was constant throughout the winter, and rats would scurry by the kids' feet as they raced down the corridors to shower at night. In summer, the iron roof baked families, and tempers flared among the men who gathered around to drink.

Debbie and my uncle Phil went to the primary school across the road. They never fitted in and classmates yelled insults at them as they walked home, hand-in-hand with my mum, back to the hostel. In high school, things were no easier. Mum recalls Debbie coming home one day with a busted lip after a group of girls attacked her at a bus stop. The family was poor, they were Yanks and they were targets. At home, the fresh start hadn't worked: fights were louder than ever and Mum found Jack's bottle of scotch in a small cupboard near the bed, exactly where he kept it in their house in West Virginia.

No one has ever said my grandfather was physically violent, but the screaming matches were loud enough to rattle neighbours, and financial troubles fanned his temper. As Jack sunk pay cheques from his job at the paper mill into horses and long afternoons at the Matraville Hotel - eventually losing the house they moved into after the hostel - the fighting intensified.

I never knew my grandfather, but I'll never forget what Mum's cousin "Catfish" told us when we met up with him in West Virginia 37 years after the family left: "We were so worried about you guys going off with Jack - we thought he was going to kill her [Grandma Iris]." After hard, lonely days at school, this was the home Aunty Deb came back to.

Through her annotations, I learnt that while she struggled socially in high school, she excelled academically: her "English teacher encouraged [her] negative poetry". She got into university, but dropped out after six months: studying pulled too much focus from her weight control. She later worked at a bank - a job that, along with the one she had at Franklins, allowed her to direct her efforts inward, and ravaged her self-esteem. With every scrawled note and highlighted passage, it's as if she's fighting to understand herself and her condition. There are hideous confessions - "I'd be on scales all day pleading to be nothing" - and questions - "Do I want to get rid of this or not? Seems not." But there's also steel. One Howard-Taylor passage stands out, underlined in a flourish of aggressive strokes: "You are not insane, you are anorexic. You are not hopeless. This isn't you: this is anorexia."

I meet lucy howard-taylor at a bookstore cafe in October, 2013. I hand her Debbie's copy of her book. "Wow," she says quietly, eyes on the pages. "I can't even tell you what it's like to see something so personal to me sort of ... co-opted. It's really very moving, but also very, very strange."

Howard-Taylor was only 19 when Biting Anorexia was published in 2008 and says that as she wrote it, "the point of the book rapidly changed from a way to help myself to a way to alleviate other people's loneliness." She then qualifies this with: "Loneliness just doesn't cut it. Alone doesn't cut it. It's total isolation - you're disconnected from the world. And a turning point for me was understanding that what I was feeling was not me, it was a hallmark of the disease." Howard-Taylor put her disease on paper, chapter upon chapter of almost unfiltered thoughts from her once desolate mind, and asked readers to recognise themselves on the page.

"Anorexia has a rhetoric," Howard-Taylor says, "and it's uncannily similar from person to person. It's so unoriginal. And I thought if I get that down, and get that out, it might just give people a little push to realise it's not just them." Talk turns to family and she tells me, "I would have done anything to not cause so much distress to my mum. She found it so hard not understanding what was going on."

When I tell her that so many of us in the family feel a deep, wrenching guilt for not having done more, Howard-Taylor says that one of the hardest things for friends and families is to realise "there is absolutely nothing you can do, that the only way they're going to get better is if they get better themselves".

I met debbie's other family at her funeral. She had been part of the congregation of St Paul's Anglican Church in South Coogee for more than a decade - that was her sitting up against the back wall, blurting out whatever questions came to mind in the middle of Reverend Stephen Bainbridge's sermons - and the parish turned out in huge numbers for the service.

It had taken some time for Debbie to warm to them - she only stayed around for post-communion afternoon tea after years of invites. By the end, though, she was hanging back regularly, asking Bainbridge theological questions and talking to others. She even started helping out in the kitchen during the church's weekly kids' club.

Debbie grew close to several people at St Paul's, especially pastoral worker Leonie de Groen. A few years before she died, police had stopped Deb while she was running on the side of the road and forced her into a paddy wagon; they had asked to see where she lived, perhaps thinking she was drunk or on drugs, and, being intensely private, she had refused. Debbie was wary of people, but when de Groen wrote a letter of complaint to the police following the incident - Debbie had been bruised as they forced her into the vehicle - a trust was earned. In her final years, it was de Groen who drove Debbie to and from doctors' appointments as her bones began to crack.

I've learnt from the parishioners that Debbie spent much of her last month alive organising a surprise birthday party for another member of the congregation. De Groen recalls that Debbie seemed to be doing well: she was thinner than ever, but had stood up to speak at church - something I could never imagine - telling people what they needed to do for the party. The party went well, and Debbie even had a sit-down lunch with the birthday girl the following Sunday. She died just two days after that. A friend had gone to pick her up for a doctor's appointment and could not open the door to her flat. Debbie was inside, collapsed on the floor, unable to move.

De Groen says the church family was struck with grief when Debbie died. But "in one sense, her battle was over - her battle with herself and with what she thought others thought of her - and I was thankful for that. I believe in what Jesus said about the Resurrection, and I know that when we meet up again in heaven, she's going to be whole and sound and well covered with flesh. And running. And it won't be a shuffle, it will be a real, healthy run."

Butterfly Foundation for Eating Disorders: 1800 334 673

This article originally appeared in Good Weekend.