Britain's largest supermarket, Tesco, last week rebuffed calls from MPs to use its massive customer database to wean junk food-buyers -- and in particular children -- from their increasingly unhealthy eating habits.

Called to give evidence before the House of Commons select committee on health, Tesco director of government affairs David North rejected suggestions that data generated by the chain's customer loyalty programme be used to identify and target heavy purchasers of foods high in fat, sugar and salt.

Such healthy diet messages, opined North would be "inappropriate" with some customers thinking it patronising or draconian.

Number two in the UK market, Wal-Mart owned Asda, agreed -- although it runs no loyalty programme itself, instead relying on its parent's 'everyday low prices' strategy. Stores have no 'moral duty' to promote better eating habits among their customers, said Asda's head of non-branded products Penny Coates.

But true to its recently acquired Ozarkian shrewdness, Asda aims to have it both ways by testing the waters of morality to see if they boost revenues.

From the new year, three in every twenty checkouts at all 265 Asda outlets will offer portions of fruit and other healthy snacks alongside the usual array of chocolate and candy products.

This -- for the time being at least -- should satisfy parent-pestering kids, politicians and the anti-junk foods lobby, as well as the combined muscle of Cadbury, Mars and Nestlé.

The parliamentary committee is currently holding an Inquiry into Obesity, in which food advertising is among the terms of reference.

Data sourced from: BrandRepublic (UK); additional content by WARC staff