The broadcasting regulator drew up its controversial proposals on the advertising of junk food for children after being lobbied on 29 occasions by the food and advertising industry, records show.

The meetings took place between May 2005 and last month. In the same period, Ofcom saw health and consumer groups on four occasions.

Campaign groups are now considering boycotting Ofcom's consultation on the proposed restrictions on advertising, saying they are too weak and put the interests of industry before the wellbeing of children.

They had wanted junk food advertising banned before the 9pm watershed to protect children of all ages.

Ofcom's proposals rule out that possibility. Ofcom spokeswoman Kate Stross said: "The cost to broadcasters of a ban on such advertising pre-watershed would be very high indeed. We came to the view that it would be disproportionate." It has been estimated that a ban on junk food and drink advertising before 9pm would cost broadcasters up to £240m a year.

Instead, Ofcom has suggested three options, including a ban on junk food ads during programmes targeted at children under 10, which would cost broadcasters £28m a year in lost revenue.

Ofcom was asked by culture secretary Tessa Jowell two years ago to produce targeted plans to curb advertisements of unhealthy foods to children. The move followed a pledge from the Department of Health in its white paper to tackle the marketing of unhealthy products to children.

But, according to campaign groups, industry lobbying has dominated Ofcom's work on the issue.

Ofcom defended its suggested curbs yesterday, saying they were "proportionate" to the "complex problem of obesity".

The records were obtained under a freedom of information request by Sustain, a coalition of 160 health and consumer groups.

They show that Ofcom met representatives from broadcasters of children's programmes, the food industry and advertising industry 29 times between May 2005 and last month. Turner Broadcasting, which owns CNN and the Cartoon Network, Nickelodeon, ITV, Channels 4 and 5, and the satellite and cable broadcasters group all met Ofcom, as did the Food and Drink Federation, Kraft, Unilever and Cadbury Schweppes.

Twelve meetings with industry took place before the first with health groups was held.

Mary Creagh, MP for Wakefield and sponsor of a private member's bill on children's food, said: "I am disappointed by Ofcom's lack of consultation with health and consumer campaigners. They have ruled out a 9pm watershed, which is the only way to stop junk food advertising to children and tackle the timebomb of childhood obesity. Advertisers are now planning their autumn campaigns, and these delays will mean that they will avoid any changes to the broadcast code before 2007."

The consumer watchdog Which? said the Ofcom proposals would not address the issue of obesity. "Even the toughest of the weak options proposed by Ofcom would not cover the programmes children are actually watching," Which? policy expert Michelle Smyth said.

Ms Stross said: "There are a lot of players in industry and we say yes if they want to see us. Consumer groups tended to come to see us together."