In the research by the Office of the Children's Commissioner, children said they were confused about which foods were healthy and which were not, and complained about mixed messages they are receiving from the media, schools and their parents.
They feel that confusing claims on products, celebrity endorsements and the lack of familiarity with healthier brands resulted in children being unable to make sensible food choices.
Children are appealing for the government to impose restrictions on advertising to prevent food companies from licensing cartoons and films and targeting them with special offers and giveaways to endorse unhealthy products.
In addition, they asked the government to work with food manufacturers to improve the nutritional quality of their products, to make healthier food cheaper and more freely available, and to require manufacturers to clearly label unhealthy food.
The results come at a time when media watchdog Ofcom is considering four proposals looking at how junk food should be advertised to children. These proposals include a full ban before the 9pm watershed. A decision is expected next month.
Professor Sir Albert Aynsley-Green, children's commissioner, said: "We need urgent action to tackle the rise in childhood obesity, and reducing children and young people's exposure to unhealthy foods would make a significant contribution to this.
"This should include the introduction of a 9pm watershed ban of television advertising of unhealthy foods and greater regulation of non-broadcast food marketing and promotion that permeates almost every aspect of young people's lives."
Ellie Lewis, report author and National Children's Bureau project development officer, said: "Children and young people know that many of the foods and drinks heavily marketed to them are unhealthy, but the 'fun factor' used by advertisers often wins them over. We need to be smarter about how we promote healthy food."
With 'Jamie's School Dinners' back on screens tonight, this research supports Jamie Oliver's drive to educate parents about healthy food.
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