Frank Duckworth, 51, spent several days in hospital after he became unwell only hours after landing in the US on a flight from Heathrow.
The incident in October 2010 began a chain of events which saw Mr Duckworth fear for his future at the company as he was restricted to duties on the ground.
An employment tribunal today ruled that the flight attendant had been a victim of disability discrimination and awarded him compensation.
Mr Duckworth already suffered from diabetes and coeliac disease – a disorder triggered by a reaction to gluten – when he boarded the routine flight from London to Las Vegas on October 4, 2010.
But he claimed a mushroom risotto which he ate while looking after passengers aggravated his conditions and made him severely ill.
He said the risotto was the only meal option offered to him on the long-haul flight.
Mr Duckworth was admitted to hospital suffering from sickness and diahorrea and remained there for several days before being cleared to return home.
When he got back to Britain, a doctor appointed by BA decided he was unfit to fly
He managed to overturn the ruling in July last year, but even then found his move to short-haul flights was hit by delays.
Tribunal judge Andrew Matthews concluded today that BA staff had blocked Mr Duckworth’s move to return to the air.
In a written judgment, the judge said staff had not acted quickly enough to get Mr Duckworth onto short haul flights.
He said BA had told Mr Duckworth there were no jobs when in fact ‘hundreds’ of staff had moved across from the company’s long-haul Worldwide division to short-haul duties.
The tribunal panel said BA had ‘failed to acknowledge the duty at all’ to avoid discrimination.
‘There was, therefore, an unreasonable delay of some six months amounting to a failure to take such steps as were reasonable and discrimination.’
The panel added that the delay had caused Mr Duckworth ‘upset and anxiety’.
The tribunal awarded Mr Duckworth £6,000 compensation ‘in respect of injury to feelings’ and £2,505.60 for loss of earnings he would have received in long-haul cabin crew on top of his basic wage.
No costs were awarded to either party.
Mr Duckworth was only given permission to fly again on May 13, just two weeks before his tribunal case was due to begin.
In a written statement to the tribunal in Reading, Berkshire, Mr Duckworth said: ‘I’ve had my diabetes and coeliac issues under control for well over 12 months.
‘However, due to the way I have been treated by BA I’ve been experiencing anxiety and mood swings which is bringing on real fear of what is going to happen to me with regard to my job and income.
‘I’ve had sleepless nights and really felt down about my situation.’
He added: ‘I believe I was being pushed out and forced to leave British Airways and from a job which I’ve done well and enjoyed for over 20 years.’
Doctors have never provided definitive confirmation that the mushroom risotto was the source of Mr Duckworth’s illness.
Once back in the UK he was sent to see British Airways appointed doctors and on January 6, Dr Richard Caddis delivered the damning verdict he was not fit to fly.
His diabetic consultant, Adrian Walker, disagreed and at one stage blasted the company for ‘being unfair’ to him, the tribunal heard.
It was only after being seen by a different medical expert, Dr Mark Popplestone, on July 21 that he was cleared to return to short haul flights, as long as he did not stay overnight for the first three months.
However, the struggle continued as he was told there were no vacancies on the 3,000-strong, short haul European fleet, despite an email being sent out in October saying numerous posts had been filled in the last few months.
Mr Duckworth, of Stoke on Trent, Staffordshire, said he believed he would have been dismissed by the company if he had not taken legal action.
He complained that he had still not been granted gluten-free meals onboard the planes.
He said: ‘I’ve been attempting to return to work as an air steward since October 2010, I’ve been passed fit by BA’s own doctor for flying duties since July 21, 2011, and yet I was only allowed to return to flying duties for the first time on May 13, 2012.
Katja De Mel, BA’s inflight business manager, said: ‘The incident in Las Vegas was not the first.
‘Frank had had similar episodes previously while he was down route on other trips.
‘I understand from British Airways Health Services (BAHS) that the incidents are caused by an adverse reaction of both Frank’s conditions.
‘I was informed that if Frank has food that is not gluten free this causes him to have an adverse reaction on account of his coeliac disease, which in turn effects his diabetes and makes it difficult to regulate his insulin levels.
‘I understand that this reaction is what caused Frank to require urgent medical attention.’
Talia Barsam, representing BA, disputed claims the company had failed to make ‘reasonable adjustments’ to Mr Duckworth’s working life so that he could continue to do his job despite his disability.
She said: ‘All of the transfers going on were being looked at simultaneously and given the nature and complexity of managing a number of cabin crew suffering with disabilities, it’s not surprising it takes the time period it takes.
‘That’s not a failure to make reasonable adjustments.’