Guo, from Hubei's provincial capital Wuhan, started dieting in 2004 when she was just 19. She thought she was too fat. She cut down food to a minimum, drank coffee without food every morning, and tried to still her hunger pangs by drinking just water.

She also found out that if she pressed down on her stomach after eating, she could induce vomiting, and she started doing that after every meal.

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Her weight dropped rapidly from 56 kg to 48 kg, and for her height at 1.6 meters tall, she became underweight. Still, she considered herself too fat and she weighed every bite of food and exercised rigorously.

"I was addicted to throwing up," Guo says, describing her bulimic condition. "But I felt I had achieved something. I didn't realize I was ruining myself."

Her personality soon changed, battered by constant hunger and plagued by fears of being overweight. Although she was a naturally gentle person, she started yelling at people all of a sudden. At other times, she would fall totally silent.

In 2010, her worried family forced her to seek treatment and she was diagnosed with anorexia nervosa. She gradually recovered after a course of medication and psychotherapy sessions, but she suffered from many relapses.

After being hospitalized in Wuhan five times, she was sent to the Peking University No 6 Hospital a few months ago. By then, she weighed only 35 kg, and her food intake was only a fourth that of the average adult.

"If time could turn back, I would never do these silly things," Guo says. "It's so hard to get rid of the illness."

Guo was lucky to be diagnosed early before more comorbid mental disorders set in - such as depression, anxiety disorders and obsessive-compulsive disorder.

"Many patients have other mental disorders and physical complications when diagnosed," says Han Xueqing, a mental health specialist with Tongren Hospital in Beijing. "It is hard to recover when the condition becomes complicated. Unfortunately, getting an early diagnosis of anorexia nervosa in China is like winning a lottery."

The odds are poor because the disorder is relatively "new", and it develops so slowly that both the patient and those around her may not be aware in the initial stages.

When the excessive weight loss and avoidance of eating finally become obvious to family members, they may seek medical help. But very often, because they are not aware that anorexia is actually more a mental than a physical disorder, the patient may be brought to a digestive tract or neurological diseases specialist, Han explains.

Yu Xiao, 22, is one such patient who was wrongly diagnosed.

The Yangzhou native developed anorexia in her freshman year in college in 2008. She dieted so vigorously that by her second year at college, she was suffering from amenorrhea due to severe weight loss.

Her family sought treatment in Yangzhou, Jiangsu province, and Shanghai, and she was medicated for irregular menstruation and digestive tract diseases. The medication proved ineffective and only made her more uncomfortable.

"Eating is easy for other people, but for me, it was very hard," Yu says. "I was hungry, but I didn't want to eat. I was afraid of putting things into my stomach, because I thought it would make me ill."

And even after food, she would exercise rigorously, thinking that exercise would help expel the food.

Her family did everything they could to tempt her to eat. Her mother thought she was being capricious, and conversation between them was concentrated on eating and gaining weight - so much so that they were quarreling about it.

"There was nothing left in my life except eating or not eating," Yu says. "I wanted to please them, but I couldn't persuade myself to eat. Life seemed hopeless and I gradually changed into another person. I was like the walking dead, but sometimes I would shout at people."

In late 2011, she was finally diagnosed with anorexia in a hospital in Yangzhou, and in early 2012, she was admitted to Beijing Huilongguan Hospital for treatment, at 1.7 meters tall and weighing less than 40 kg. She was extremely underweight, and suffering from depression and obsessive-compulsive disorder.

After being treated for about two months, she gained 10 kg and started eating again.

"I don't blame the doctors in Yangzhou and Shanghai. Few people are aware of this disorder. Who would think of such a thing?" Yu says.

"Our society is more tolerant of people who are thin rather than fat. But if I had known there was such a disorder, I would never have hurt myself in the first place."

Contact the writer at liuzhihua@chinadaily.com.cn.