It was when she was passed an anonymous note in Waitrose by a complete stranger that Anna Wyatt's life changed.

The student from Norwich, then a 20-year old who weighed less than six stone, was battling anorexia but not responding to NHS treatment.

Instead it was a handwritten note, hastily scribbled and passed to Miss Wyatt while she was paying for groceries, which sparked her recovery.

'The note changed my life,' Miss Wyatt said.

'It was an incredible thing for the person to do, to be brave enough to walk up to a stranger and offer that help.'

The note, which was written by blogger Ella Crouch, directed Miss Wyatt to her blog where she details her recovery from an eating disorder.

The simple gesture turned Miss Wyatt's life around - and 18 months on she is well on the road to recovery.

'Having anorexia is like having the conscious part of your brain put in a very small box, which is surrounded by a much larger fog swirling all around inside your head,' she said.

'You know what is sensible but there is something that stops you from doing it.'

There are an estimated 1.6m people with eating disorders in the UK, of which 10pc of cases are anorexia related.

Miss Wyatt developed anorexia while studying at the University of Exeter and her weight plummeted.

She said there was no particular trigger which caused it.

Miss Wyatt postponed her second year at university to live at home and received treatment from Norfolk Community Eating Disorder Services.

But she said the treatments offered, such as cognitive behavioural therapy and cognitive analytic therapy, were fruitless because they focused on changing her mindset rather than give her a physical treatment,

Her weight continued to drop down until the note was pressed into her hands.

'I had a look on Ella's blog and for the first time thought 'this is the way the to go',' she said.

'If she hadn't given me that note I think I'd have been hospitalised pretty soon as I would have kept losing weight.'

Ms Crouch was treated by personal trainer Leon Bustin, who runs sessions at Carrefour Health and Beauty, Norwich, and Miss Wyatt contacted him for a consultation.

Her treatment with him became focused on building up muscle and weight at the gym, and gradually improving her eating habits.

'I found I needed to put on weight first, and then the mindset could change,' she said.

Miss Wyatt is now raising money for charity to trek to Machu Picchu in Peru next August.

The charity provides equipment to a hospital in northern Sri Lanka.

To donate visit www.justgiving.com/annawyatt

Have you conquered an eating disorder?

Email nicholas.carding@archant.co.uk