Leading doctors in Britain will today demand tough government action to curb the nation's addiction to unhealthy food, and so help halt spiralling rates of obesity, diabetes and heart disease.

Senior medical figures want to stop fast-food outlets opening near schools, restrict the advertising of products high in fat, salt or sugar and limit sponsorship of sports events by fast-food producers such as McDonald's.

They also want "fat taxes" to be imposed on foods that cause the most dietary harm and introduce cigarette-style warnings for schoolchildren about the dangers of a bad diet.

Professor Terence Stephenson, president of the Royal College of Paediatrics and Child Health, said the consumption of unhealthy food should be seen to be just as damaging as smoking or binge drinking.

"Thirty years ago, it would have been inconceivable to have imagined a ban on smoking in the workplace or in pubs, and yet that is what we have now. Are we willing to be just as courageous in respect of obesity? I would suggest that we should be.".

Professor Stephenson's comments will reignite the debate over the role of regulation in tackling public health problems.

Health Secretary Andrew Lansley said last week that "no Government campaign or programme can force people to make healthy choices. We want to free business from the burden of regulation, but we don't want, in doing that, to sacrifice public health outcomes".

Mr Lansley has alarmed health campaigners by saying manufacturers of potato crisps and sweets could play a central role in the Change4Life campaign, the centrepiece of government efforts to boost healthy eating and fitness.

He has also criticised chef Jamie Oliver's high-profile attempt to improve the quality of school lunches in England as an example of how "lecturing" people was not the best way to change their behaviour.

Professor Stephenson suggested potential curbs could include banning TV ads for foods high in fat, salt or sugar before the 9pm watershed and limiting them on billboards or in cinemas.

"If we were really bold, we might even begin to think of high-calorie fast food in the same way as cigarettes - by setting stringent limits on advertising, product placement and sponsorship of sports events."

Professor Dinesh Bhugra, president of the Royal College of Psychiatrists, said: "Some types of processed foods are harmful to the physical, and consequently mental, health of individuals.

"There ought to be serious consideration given to banning advertising of certain foods and certain processed foods and to levying tax on fatty, unhealthy foods."

He said school pupils needed to be told more about the effects of bad diet. He also urged councils to impose "fast-food free zones" around schools and hospitals.

Mr Lansley received unexpected support from Professor Stephenson and Professor Steve Field, chairman of the Royal College of General Practitioners, who said he was right to stress the importance of personal responsibility, as well as government action, in ending the country's dysfunctional relationship with food.

Both strongly criticised parents for setting their children a bad example by overeating, serving poor-quality food and exercising too little.

"Parents are role models for their children. It's crucial that they set the tone for what the children eat and their physical activity," said Professor Stephenson.

"The fact that one-third of our children are now overweight ... must mean their parents are allowing them to eat excessive amounts of food and not ensuring they take enough exercise."

Professor Field, a family doctor in Birmingham, said: "Too many parents show too little responsibility in the vital business of passing on good eating and drinking habits to their children."

A Health Department spokesperson said: "We need to create a new vision for public health where all of society works together to get healthy and live longer. This includes creating a new 'responsibility deal' with business, built on social responsibility, not state regulation."

Into Battle

Doctors are urging a crackdown on junk food. They want:

* To stop fast-food outlets opening near schools.

* To restrict advertising of products high in fat, salt or sugar.

* Fat taxes to be imposed on foods that cause the most harm.

* Cigarette-style warnings for kids about the dangers of a bad diet.