British politicians will ask supermarkets and food and drink firms to justify their marketing strategies as the debate about child obesity intensifies.

The House of Commons Health Select Committee plans to summon Cadbury, Coca-Cola, McDonald's and the big supermarket chains to answer accusations that they deliberately target children when selling fattening and potentially health-damaging products.

The committee is looking at various solutions to the problem of rising child obesity: a ban on food and drinks firms advertising to children; an increase in the amount of school time devoted to sport; a tax on fatty foods; the removal of high-calorie products from school snack machines; and tax breaks for gyms.

It is a controversial issue. Last month the Food Standards Agency issued a report that claimed: "Food promotion is having an effect, particularly on children's preferences, purchase behaviour and consumption."

However, many marketers insist the chief problem is not a rise in children's intake of calories but their increasing failure to take exercise.

Committee members will visit the US next week to consult with health professionals, advertisers, and the Denver-based America on the Move group that gained for Colorado the title of 'the leanest state in the union' for its campaign to encourage its citizens off the couch and into exercise.

The committee's chairman David Hinchliffe, a leading figure in the political campaign against cigarette ads, believes there are similarities between that issue and food marketing. "We have a crisis on our hands," he declared. "The parallel between the fight against the tobacco companies advertising and the food firms is not exact, but it is there."

Data sourced from: MediaGuardian.co.uk; additional content by WARC staff