New rules banning the use of celebrities to advertise junk food during television programmes designed to appeal to the under-10s were announced yesterday as part of proposals to tackle obesity in children.

The rules, which come into effect this autumn, will banish Gary Lineker's Walkers crisps commercials and Beyoncé's Pepsi endorsement from ad breaks during children's shows. Film tie-ins will also be banned, while other measures will outlaw advertising designed to encourage children to pester their parents for foods that are high in salt, sugar and fat.

The package was unveiled by the industry's regulator, Ofcom, which vowed to cut by half the amount of food and drink advertising seen by children in the UK, one in three of whom are now classified as overweight or obese.

More radical proposals - on top of the new rules announced yesterday - are the subject of consultation and will be introduced next year. Ofcom's chief executive, Stephen Carter, said: "With childhood obesity, the case for targeted action has been made. But which action, and how this should be implemented, is the final stage of consultation."

But health food campaigners rejected the plans, accusing Ofcom of caving in to pressure from food giants.

Sustain and the National Consumer Council said they would continue to demand a ban on junk food advertising before the 9pm broadcasting watershed. They point out that programmes such as Coronation Street are watched by millions of children.

Campaigners also argued that almost two years after Ofcom was first charged with looking into the issue in a government white paper, the new proposals smacked of delaying tactics. Children's TV channels will be given three years to put into effect the proposals that will be introduced next year.

"The food industry's extensive lobbying appears to have paid off," said Richard Watts, of Sustain. "Ofcom has put the interests of the food and advertising industries before the interests of kids' health."

The National Consumer Council's chief executive, Ed Mayo, said: "None of these proposals goes anywhere near what's needed to redress the imbalance in [TV's] advertising of unhealthy food to children and so help tackle childhood obesity. Ofcom should have been bolder."

But Mr Carter said: "Some form of volume restriction is justified and proportionate." He said there was "no easy one-size-fits-all" solution, which was reflected in the lack of consensus.

Three more radical proposals are being considered by Ofcom, all of which include a ban on food and drink advertising to pre-school children on the basis that under-fives cannot distinguish between advertising and programmes. The regulator claimed this would cut the amount of food and drink advertising seen by children by half. The first option is to ban adverts for food high in salt, sugar or fat during children's programmes or those shows that attract a high number of young viewers, such as The Simpsons and some music and reality shows. The second idea is to ban all food and drink advertising and sponsorship in programmes specifically made for children under nine. The third would limit food and drink adverts to 30 seconds an hour during times when children were most likely to be watching, and 60 seconds an hour between 6pm and 8pm.

The first proposal is seen as most likely to come to fruition, given that the second would also ban adverts for healthy food and the third would be vigorously opposed by broadcasters such as ITV.

Implementation of either of the first two proposals would hit the finances of dedicated children's channels the hardest. Ofcom also offered broadcasters and advertisers a fourth route, allowing them to present their own proposals.

Advertisers and broadcasters, which have been lobbying regulators and the government, yesterday repeated their view that any measures had to be "practical and proportionate". ITV said that any action that hit advertising revenues would lead to lower programme investment.

Ofcom said its proposals were designed to be part of a wider solution, including food labelling and healthier lifestyles, and to dovetail with the conclusions of a Department of Health forum looking at other forms of advertising and promotion.

On the table: The new rules

· Avoid anything likely to encourage an unhealthy lifestyle or poor eating habits

· Avoid asking children or their parents to buy the products

· Avoid promotional offers

· Stop using celebrities or characters in adverts aimed at under-10s

· Avoid condoning excessive consumption of food or drink

Plus one of the following four options:

· No advertising of products high in fat, salt, or sugar during pre-school programmes

No advertising of such products during children's programmes

No such advertising during shows of "particular appeal" to children up to nine years, for instance The Simpsons

No sponsorship of such shows by products high in fat, salt, or sugar

· No food or drink advertising during pre-school programmes

No food or drink advertising during children's programmes

No food or drink advertising during programmes of "particular appeal" to children up to nine years

No sponsorship of the above programmes by food or drink products

· No food or drink advertising during pre-school programmes

Food and drink advertising and sponsorship limited to 30 seconds an hour between 6am and 9am and 3pm to 6pm on weekdays

Food and drink advertising and sponsorship limited to 30 seconds an hour between 6pm and 1pm at weekends

Food and drink advertising and sponsorship limited to 60 seconds an hour between 6pm and 8pm on week nights or 1pm and 8pm at weekends

Advertising limit for children's channels of 30 seconds an hour

· New proposals from broadcasters and advertisers that would reduce by 50% the amount of adverts featuring products which are high in fat, salt or sugar.