But if the pressure is taking its toll on Martin Paterson, it does not show. He is a born storyteller, chuckling heartily as he reels off one self-deprecating yarn after another – a 'heartbreaking' tale of his failures as a gardener; an 'awful' archeological dig that resulted in him spending hours on his hands and knees covered in dirt; the announcement that he is 'excellent at playing golf badly'. Paterson has a tendency to peer over his glasses and whisper or put on accents to add drama or comic effect.
About Kelly's speech he says, without a hint of bitterness: 'I congratulate my colleagues [at the Department for Education and Skills] – many of whom I trained – on deflecting media coverage away from school meals and onto vending.'
Paterson is used to dealing with bad press, having worked in Whitehall for 12 years. But even he was surprised by one journalist's charge that junk food could lead to drug addiction. 'There is a bit of a difference between a Curly Wurly and heroin,' he points out.
The 50-year-old father of three comes from a family of socialists, his grandfather having been instrumental in forming the Labour Party in Scotland. But he describes himself as 'apolitical' and says his job is 'like the position I'd imagine a barrister to be in. Your job is to explain the line, to present it. It helps if you believe it, and you must never tell a lie. You must keep your energy levels up. I find beer helps. And be honest. Don't sell your granny for a headline this week – there's still news next week'.
Jackie O'Sullivan, a former colleague from Paterson's Whitehall days and The Food and Drink Federation, says: 'His advice was always much sought after, because he had an unerring news sense, an unfailing knack of knowing what to watch for.'
Clearly news is Paterson's life. The TV opposite the desk in his office – a bright room in an otherwise drab building in the heart of London's theatreland – has Teletext headlines on permanent display. He skims the broadsheets and reads cuttings every morning. He nurtures relationships with journalists – as well as politicians and federation members – through countless lunches and dinners.
Paterson is also accustomed to media appearances – he racked up six on Newsnight last year, and his younger self, sporting an ankle-length quilted leather jacket and bushy moustache, was caught by the world's news cameras when he was working with the cabinet during Margaret Thatcher's resignation in 1990.
Originally a photographer, Paterson 'slid into PR sideways', being invited to work for the US forces in Germany after some of his pictures were exhibited in the White House. He then entered Whitehall, working for the Ministry of Defence ('a tough job for a civilian – the soldiers were a crusty bunch') and in education ('a battleground'). Then, after years of anxious calls in the middle of the night from ministers, he joined the federation.
Much has changed during his time at the organisation: 'Eight years ago a lot of people – even here – thought trade bodies were dusty and peculiar. But I took the view we should be active and transparent. Having a better profile can't hurt – policies happen in the glare of the media spotlight, so we need to be inside that light.'
But if junk food is not to blame for obesity, why is Kelly taking action?
Because, says Paterson, it would be far more difficult for the Government to challenge our sedentary lifestyles, 'to tell the nation to get off its lardy backside and do a bit of tai chi'.