Academics and health experts are divided on the effects of junk-food advertising.
Ban all ads for junk food. Stop TV personalities doing commercials for sugar-laden breakfast cereals and banish pester-power promotions for fast food from the airwaves. Then the quarter of Australian children who are overweight, including the one in 20 who are obese, would trim their overfed tummies, wouldn't they?
Perhaps not. Such a social revolution is doubtful - and not merely because the Federal Government has made it clear a ban is out of the question, preferring advertisers and TV stations to regulate themselves on junk-food advertising matters.
It's in doubt because, according to public health researcher Owen Carter, the link between television watching and childhood obesity is "surprisingly weak". Based on a review of studies that compared how many hours of television children watched a day with how fat they were, he says, a child's TV viewing can only affect about 1 per cent of body weight.
Carter, who recently published a review of literature on the link between childhood obesity and food advertising on Australian television in the Health Promotion Journal of Australia, found no direct evidence to link junk-food advertising with childhood obesity.
He argues that, by deduction, any contribution of junk-food ads "has to be less than the 1 per cent total" in the difference TV watching makes to children's weight. "That is, half of bugger all," he says.
Further, Carter found a lack of exercise was not the great problem among those who watch TV. Children who watch less than the average of two hours a day simply replace TV with other sedentary activities such as reading and listening to music.
Overall, Carter makes the heretical finding that there is little evidence children today are more sedentary than their parents or grandparents.
Carter does not quibble with the fact childhood obesity rates have tripled over the past 20 years. But he blames parents for feeding their children too much junk.
Parents who regularly consume junk food and soft drinks are much more likely to let their children do the same, Carter says. "This is why a child with obese parents is 10 times more likely to be obese [than children without obese parents]."
Carter, a research fellow at the Centre for Behavioural Research in Cancer Control at Perth's Curtin University of Technology, has a big interest in fighting obesity, as it is related to increased deaths from various forms of cancer. His $120,000 funding for the study comes from the Australian Research Council.
"I fully expected there to be plentiful and sound evidence of a significant relationship between junk-food advertising and childhood obesity," he says. "However, the deeper I delved, the more confused I became, because I couldn't actually find any evidence at all.
"The only data I found contradicted this position entirely, until I was begrudgingly forced to accept that there actually was no evidence of a relationship at all."
From Sunday, the world's health experts will gather in Sydney for the 10th International Congress on Obesity. High on the agenda is a debate about whether childhood obesity can be reduced "without the heavy hand of government", such as putting the brakes on advertisers.
VicHealth chief executive Rob Moodie will be arguing the case for government intervention. He dismisses Carter's paper as "more narrative than systematic review" and says its findings contradict systematic US and British reviews.
Moodie says it is very difficult to conduct studies that would give you a statistic on how much an impact food advertising has on weight because there are so many other factors that can't be measured.
Children today are more sedentary than their parents or grandparents, he argues, and are heavily influenced by junk-food advertising. Since the mid-1970s, Moodie says, Australia has suffered a "market-driven obesity epidemic", in which food manufacturers worked out how to "ram a lot of calories down your throat" at the same time as backyards started getting smaller and children started playing less often in the street and thus getting less exercise.
* 10th International Conference on Obesity, Sydney Convention and Exhibition Centre, September 3-8, ico2006.com.
OVERSEAS RESEARCHERS CHEW THE FACTS
The US Institute of Medicine's Food Marketing to Children and Youth report released last December found "strong evidence" television advertising influences the food and beverage preferences and requests of children aged two to 11. However, there was insufficient evidence of its impact on the preferences and requests of children aged 12 to 18.
There is "strong evidence" TV advertising is associated with adiposity or fat in children, the US researchers found - although on current evidence, the Institute of Medicine says, it cannot be said TV ads cause children to get fat.
A systematic review conducted on behalf of Britain's Food Standards Agency in 2003 found a "probable" link between the content and number of junk food advertisements and children's weight gain.
"I fully expected there to be plentiful and sound evidence of a significant relationship between junk-food advertising and childhood obesity," he says. "However, the deeper I delved, the more confused I became, because I couldn't actually find any evidence at all.
"The only data I found contradicted this position entirely, until I was begrudgingly forced to accept that there actually was no evidence of a relationship at all."
From Sunday, the world's health experts will gather in Sydney for the 10th International Congress on Obesity. High on the agenda is a debate about whether childhood obesity can be reduced "without the heavy hand of government", such as putting the brakes on advertisers.
VicHealth chief executive Rob Moodie will be arguing the case for government intervention. He dismisses Carter's paper as "more narrative than systematic review" and says its findings contradict systematic US and British reviews.
Moodie says it is very difficult to conduct studies that would give you a statistic on how much an impact food advertising has on weight because there are so many other factors that can't be measured.
Children today are more sedentary than their parents or grandparents, he argues, and are heavily influenced by junk-food advertising. Since the mid-1970s, Moodie says, Australia has suffered a "market-driven obesity epidemic", in which food manufacturers worked out how to "ram a lot of calories down your throat" at the same time as backyards started getting smaller and children started playing less often in the street and thus getting less exercise.
* 10th International Conference on Obesity, Sydney Convention and Exhibition Centre, September 3-8, ico2006.com.
OVERSEAS RESEARCHERS CHEW THE FACTS
The US Institute of Medicine's Food Marketing to Children and Youth report released last December found "strong evidence" television advertising influences the food and beverage preferences and requests of children aged two to 11. However, there was insufficient evidence of its impact on the preferences and requests of children aged 12 to 18.
There is "strong evidence" TV advertising is associated with adiposity or fat in children, the US researchers found - although on current evidence, the Institute of Medicine says, it cannot be said TV ads cause children to get fat.
A systematic review conducted on behalf of Britain's Food Standards Agency in 2003 found a "probable" link between the content and number of junk food advertisements and children's weight gain.
Obesity Debate
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