The thorny issue of advertising food products to children hit the headlines again yesterday with the publication of a document by the UK Food Standards Agency confirming possible links between advertising and eating patterns.
The food industry has been vilified in some quarters for the creation and promotion of fatty, sugary and generally unhealthy food aimed at children - allegations which it has vociferously rejected - and the study suggests that there is indeed some foundation to the accusations.
Professor Gerard Hastings, whose team at the University of Strathclyde Centre for Social Marketing compiled the report, confirmed that that advertising to children does have an effect on their preferences, purchase behaviour and consumption. Furthermore, these effects are apparent not just for different brands but also for different types of food, he said.
According to the report, children's food promotion is dominated by television advertising, and the great majority of this promotes the so-called 'Big Four' of pre-sugared breakfast cereals, soft-drinks, confectionery and savoury snacks.
But while TV plays an important part, it is now part of broader campaigns, which include merchandising, 'tie ins' and point of sale activity.
As a result, the advertised diet contrasts sharply with that recommended by public health advisors, and themes of fun and fantasy or taste, rather than health and nutrition, are used to promote it to children.
"There is plenty of evidence that children notice and enjoy food promotion. However, establishing whether this actually influences them is a complex problem," said Professor Hastings.
The review tackled this problem by looking at studies that had examined possible effects on what children know about food, their food preferences, their actual food behaviour (both buying and eating), and their health outcomes (e.g. obesity or cholesterol levels).
The majority of studies examined food advertising, but a few examined other forms of food promotion.
"In terms of nutritional knowledge, food advertising seemed to have little influence on children's general perceptions of what constitutes a healthy diet, but, in certain contexts, it does have an effect on more specific types of nutritional knowledge," he said.
"For example, seeing soft drink and cereal adverts reduced primary aged children's ability to determine correctly whether or not certain products contained real fruit."
The review also found evidence that food promotion influences children's food preferences and their purchase behaviour. A study of primary school children, for instance, found that exposure to advertising influenced which foods they claimed to like and another showed that labelling and signage on a vending machine had an effect on what was bought by secondary school pupils.
A number of studies have also shown that food advertising can influence what children eat. One, for example, showed that advertising influenced a primary class's choice of daily snack at playtime.
"The next step, of trying to establish whether or not a link exists between food promotion and diet or obesity, is extremely difficult as it requires research to be done in real world settings," said Professor Hastings.
A number of studies have attempted this by using amount of television viewing as a proxy for exposure to television advertising. They have established a clear link between television viewing and diet, obesity, and cholesterol levels.
It is impossible to say, however, whether this effect is caused by the advertising, the sedentary nature of television viewing or snacking that might take place whilst viewing, the Professor warned.
One study resolved this problem by taking a detailed diary of children's viewing habits. This showed that the more food adverts they saw, the more snacks and calories they consumed.
"Thus the literature does suggest food promotion is influencing children's diet in a number of ways. This does not amount to proof; with this kind of research, incontrovertible proof simply isn't attainable. Nor do all studies point to this conclusion; several have not found an effect. In addition, very few studies have attempted to measure how strong these effects are relative to other factors influencing children's food choices.
Nonetheless, many studies have found clear effects and they have used sophisticated methodologies that make it possible to determine that these effects are not just due to chance, that they are independent of other factors that may influence diet, such as parents' eating habits or attitudes, and that they occur at a brand and category level."
The FSA said that it would draw on the conclusions of the report to inform and promote open public debate, hosting a series of meetings involving a wide range of stakeholders with an interest in, or concern about, the promotion of food to children.
The agency will then consider the outcomes of the public debate, and discuss the options available.
Organisations which have been highly critical of the food industry in the past have been quick to respond to the FSA's report. The Food Commission, one of the fiercest critics of the advertising tactics of the major food manufacturers, called the report a "call to action" and hoped that the UK government would now take firm action to combat the problem.
"Children are already eating too much fat, sugar and salt, yet we allow them to be systematically targeted with advertising for unhealthy foods. The Food Standards Agency's review provides the evidence of what parents have known all along - advertising encourages children to choose unhealthy foods and to pester their parents for them," said Kath Dalmeny, Policy Officer for the Food Commission.
"Food companies are experts at selling junk food and soft drinks to children using advertising, packaging and free gifts, but the one thing that repeatedly gets left out is good nutrition. It's time that food producers and advertisers used their expertise to sell healthier foods to children," added Annie Seeley, nutritionist and coordinator of the Food Commission's Parents Jury.
The Food Commission is one of 85 organisations calling for legislation to protect children from the promotion of foods that contribute to a unhealthy diet. The coalition is being co-ordinated by Sustain: the alliance for better food and farming.