It was in China that I saw at first hand the addictive power of sponsorship at work. I was covering the twinning of a Chinese and a British city. A well-known brewer sponsored the British city's football team and its youth side was part of the festivities, taking on the Chinese youth team in front of a big television and stadium audience.
But I'd heard that the Chinese city authorities had very nearly cancelled the match: while they were keen to imbibe British professional soccer expertise, they were less keen on the lager brand, particularly when fixed to the strip of 11 under-18s.
The Chinese are acutely aware of the problems of western youth, and terrified of importing them. I asked the British coach on tape whether he'd discussed the impact on the Chinese of his team parading on to the pitch "dressed as beer bottles". It was a question too far. "They are not dressed as beer bottles," he snapped.
All the same, at matches, training and at the inevitable banquet, the brand was very much in evidence on the young players' tracksuits and elsewhere. I was quite lucky to have attended all these functions, as after the beer bottle question, I found myself left off lists, ticketless, invitation-free and not to be talked to on the record.
It seemed as if the coach, in other respects a wise professional, had blinded himself to any moral problem with young sportsmen promoting beer.
Addiction to inappropriate sources of cash is the same as addiction to consuming unhealthy food and drink. You know it's bad for you, but you need a bit extra.
So it was extraordinary to read that members of the National Association of Head Teachers have demanded pound;10 million in compensation for the loss of income a ban on vending machines in schools would mean. The lost inches in waistlines - teachers' as well as pupils' - should be compensation enough.
Meanwhile, the people who run children's commercial television, another group supposed to have children's interests at heart, are reportedly threatening wall-to-wall junk television (ie cheap imported cartoons) if they lose revenues from junk food advertisers because of a ban.
This is rather a nasty threat: if we can't sell them junk for their mouths, we'll give them junk for their eyes and ears. And all the while advertisers can console themselves that family viewing time - for example, Coronation Street, sponsored by a chocolate maker - is just as good a place in the schedules to set out the sweets.
So should there be a voluntary code limiting the advertising of unhealthy food and drink to children? It is unlikely such a device would work. Just look at the failure of the drinks industry's "voluntary code of practice" on the sale of alcohol. An ongoing report on this code's effectiveness can be examined every weekend, written in puke, urine and blood on the streets of every UK city centre.
Voluntary codes end up being ineffective. But legislation limits freedom.
Meanwhile, those whose job it is to look after the interests of children are refusing to say no to income derived from what many would regard as inappropriately sugary sources.
And this is not a modern phenomenon. The Kellogg company - which a century ago led a backlash in the United States against overeating and poor diet by developing the first healthy breakfast cereals - became the first to perfect the manufacture of pre-sweetened cereals, with sugar. The high-minded principles of founder William Kellogg were forgotten.
By this time, the 1950s, one of Kellogg's major shareholders was a children's charitable foundation, whose interests appear to have been put before the interests of the world's waistlines and teeth.
A key function of advertising is to "overcome potential customer resistance". This is a euphemism for "sell - and damn the consequences to the buyer". When strangers offer sweeties, they usually have ulterior motives.
I would say that it's up to all those who are in a position to take money from the promotion and sale of unhealthy food and drink to "just say no" as loudly and publicly as possible.
Particularly if that money is for schools, sports, or charity.
Nick Baker is executive producer of BBC Radio 4's summer debate programme Straw Poll.