Television ads for junk food do encourage children to eat unhealthily, according to a report.
Some ads are targeted at children
While the link has long been suspected, researchers at the University of Strathclyde say they now have evidence that it exists.
They analysed over 30,000 pieces of research and found that TV ads are responsible for children eating too much sugar, fat and salt.
The Food Standards Agency called for a debate on the merits of TV food ads.
Professor Gerard Hastings and colleagues at the university's Centre for Social Marketing found that most ads for food targeted at children appeared on TV.
These are mainly for the so-called "big four" products - breakfast cereals
containing sugar, soft drinks, sweets, and other snacks.
However, in the past 10 years there has also been a rapid rise in advertising by fast food chains, which often use the offer of free gifts to tempt youngsters.
Professor Hastings said problems arose because the diet advertised on television was completely different to the recommended diet for children.
"Food is the most commonly advertised product to children, with the possible exception of toys around Christmas time," he told the BBC.
"The advertised diet varies greatly from the recommended one. It is much higher in salt, sugar and fat."
Professor Hastings said he hoped the findings would spark a public debate.
"There is a relationship between the advertising that goes on and how children relate to food, particularly what sort of things they prefer to eat and what sort of things they buy," he said.
"Let's all accept the evidence is there and let's have an intelligent debate about where we go from here. "
He rejected suggestions that TV ads for junk food targeted at children should be banned.
"I don't think a knee jerk reaction to say we should ban advertising is necessarily the solution," he said.
"This is a very complex phenomenon. Advertising is not the only thing making our kids fat.
"There are lots of things going on. We need to recognise that any response to that has to be equally sophisticated."
The Food Standards Agency, which commissioned the research, said it would be promoting a public debate to discuss the findings.
In July, campaigners from the Food Commission called for adverts for junk food to be banned.
They said many of these adverts target children and eclipse healthy eating messages.
"This report is a call to action," said Kath Dalmeny, its policy officer.
"Children are already eating too much fat, sugar and salt, yet we allow them to be systematically targeted with advertising for unhealthy foods."
Tim Lang, professor of food policy at City University in London, said the government would have to make some uncomfortable choices.
"The government has simply got to face this issue and explore how to curtail the marketing assault on children's diets."
Recent studies have raised fresh concern about the diet of children in the UK.
The National Diet and Nutrition Survey in 2000 found the majority of British children consumed more than the recommended amount of sugar, fat and salt. Obesity rates are also on the increase.
Labour MP Debra Shipley, who introduced a bill in Parliament to ban food advertising
on TV for under fives, said: "This independent report is a damning indictment
of the advertising industry's marketing strategies to children.
"It is now clear and unarguable that there is a direct relationship between
food advertising to children, poor diet, and rising levels of obesity and
Martin Paterson, deputy director general of the Food and Drink Federation,
which represents manufacturers, said: "Food and drink manufacturers take a very responsible view of advertising,
particularly of products aimed at children.
"Strict codes of practice exist to govern advertising, and these state 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."