All this is worth bearing in mind in any discussion about its role in the healthy eating debate. The decline in school sports facilities and the rise of eating on the move have played more significant roles than advertising in fuelling obesity among children. Moreover, it is widely accepted that promoting healthy living would, like any other form of public service advertising, need lots of time to work.
Strangely, that does not seem to be the case. Today, food advertisers and their agencies have been left gasping at the pace of change in the country's eating habits. So why does Britain now seem determined to do something about its weight problem? The bandwagon set rolling by Jamie Oliver, forcing the Government to act over unhealthy school meals, continues to keep obesity at the top of the consumer agenda. Meanwhile, high-profile healthy eating advocates such as Gillian McKeith keep up the momentum.
Snack-food advertisers who ignore this dramatic change in consumer attitudes do so at their peril. Last month's collapse of Golden Wonder, which once dominated the UK crisp market, should be a powerful warning of the dangers of not adapting your products (and ads) swiftly enough.
Contrast that with Walkers, which has almost 60 per cent of the UK crisp market. Last week, it ran national press ads outlining what it was doing to make its products healthier, under the heading: "You are changing and so are we."
What is happening has to be good news for agencies. For one thing, it will lessen pressures for legal restrictions on snack-food advertising to children. This has rightly been a big concern for the industry. Once one kind of advertising is banned, how long before a crusade begins against another?
For another, it enables advertising to show it is not the shallow, self-serving industry many perceive it to be. If it wants to be seen as part of the solution rather than part of the problem, there has never been a better time to prove it.