Advertising to children has always been controversial. The little darlings, it's argued, are too young to understand that advertisers may not be telling the whole truth; advertising encourages them to pester parents for expensive (and possibly harmful) toys and treats.
Much of the debate centres on television advertising for "junk" foods.
Couch potato lifestyles are contributing to obesity
But it is notoriously difficult to establish direct causal links between people's behaviour and anything they see on screen - as anyone who has followed the debate about screen violence and its effects knows.
But last month the debate about advertising and children took a new and striking turn.
Research commissioned by the Food Standards Agency apparently showed that there was a direct link between TV ads for fast foods, snacks and sweets and rising levels of obesity among children.
The report was widely covered by the press. "Study finds TV ad link to horror diet," reported the Daily Mirror. The Daily Telegraph thought the report was a "watershed" - and so important that it led the front page with it, on the day every other broadsheet led with the final day of the Hutton inquiry.
In fact the research wasn't quite the ground-breaking work it first appeared. Professor Gerard Hastings and his team at Strathclyde University had simply reviewed the existing scientific literature on the subject, sifting through 29,000 academic papers and finding 21 which they concluded demonstrated "a clear link between television viewing and diet, obesity and cholesterol levels".
The report was welcomed by healthier eating campaigners like the Food Commission, but it's far from clear what it's impact will be.
The FSA has sent a team to Sweden, where television advertising aimed at children is banned. The Swedes considered trying to impose such a ban Europe-wide when they held the presidency of the European Union, but nothing came of it.
The food industry - which spent £450m on food ads last year - and the advertising industry would oppose such a ban on grounds of principle (it would curb freedom of speech; no-one is suggesting banning car ads just because car drivers kill people) and pragmatism (it wouldn't work).
An industry lobby group, the Food Advertising Unit, gave Prof Hastings' report only a lukewarm welcome.
In a statement it said: "There is a strict statutory Code of Practice on TV advertising to children, which the advertising industry supports. It states that ads should not encourage children to eat or drink frequently throughout the day, condone excessive consumption, or suggest that confectionery or snacks should replace balanced meals."
And it said the report made no mention of other factors influencing children's eating habits and obesity, like parents, sibling and peer group pressure or the effect of reduced exercise.
But public concern about obesity may finally have reached a level that the industry cannot ignore. There may not be a ban, but further voluntary curbs on food advertising aimed at children seem inevitable.