Professor Sir Albert Aynsley-Green was speaking after the Prime Minister's speech to the Labour Party conference yesterday in which Tony Blair suggested waiting to see if advertisers adhered to a voluntary code before considering legislation.
He said: "I welcome Tony Blair's commitment to restricting junk food advertising but a voluntary code is not the answer.
"A number of high street supermarkets have not signed up to the voluntary code on food labelling, so there is no reason to believe that a voluntary code on advertising junk food would be any more effective."
As well as supporting a ban on junk food ads on television before 9pm, he called for greater restrictions on the advertising of unhealthy foods in magazines, posters, text messages, internet pop-ups and cartoon and film sponsorship.
He said: "Recent research commissioned by the Office of the Children's Commissioner shows that children and young people are struggling to make sensible decisions about food because of the multitude of messages encouraging them to consume high-fat, high-sugar, processed products," he added.
The Children's Commissioner was established in 2004 to champion the interests of children and young people.
Sir Albert Aynsley-Green launched a research project into children and young people's views on food advertising earlier this month.
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