Some of Britain's biggest food companies are targeting children with up to 40% of their television adverts, the BBC has learned.
There is concern at the effect of adverts
An investigation has found a high proportion of food commercials are broadcast during children's programmes.
Culture Secretary Tessa Jowell described the findings as "important".
She said they would be referred to the broadcasting regulator Ofcom, which is currently reviewing advertising regulations.
The government has launched a wide-ranging review into food promotion and childhood obesity
Proportion of adverts broadcast during children's TV
Haribo - 56%
Bel - 48%
Kellogs - 44%
Britvic - 41%
McDonalds - 33%
Nestle - 30%
However, Ms Jowell has expressed "scepticism" that a ban on advertising to children would provide a solution to obesity.
She points to the Wanless Report into how to tackle the problem of public health, which found that the average Briton is not eating more food.
The advertising industry, too, has insisted that there is no correlation between food advertising and obesity.
It cites the example of Sweden, where there is a complete ban on advertising during children's television, but no noticeable difference between children's bodyweight there and in neighbouring countries.
Adverts do not encourage children to eat more, it claims, but just to change brand.
The advertising industry also says there is a direct link between advertising revenue and expenditure on children's programming.
It maintains that if children's advertising was banned or restricted, commercial broadcasters would reduce or cease their investment in original programme production.
In the past 10 years, obesity in six-year-olds has doubled to 8.5%, and trebled among 15-year-olds to 15%.
The National Audit Office has projected that by 2010 one in four adults will be obese - costing the economy around £3.6bn a year.
The survey found that some food companies - including Cadbury, Coca Cola and Pizza Hut - did not broadcast a high proportion of their adverts during children's television.