David North, director of government affairs at Tesco, was appearing before members of the health select committee, which is investigating the rise of obesity among children.
Members of the committee have been asking supermarket executives to encourage customers to buy more healthy foods. One of the suggestions is that loyalty card schemes, such as Tesco Clubcard, could be used to collect data on people who buy lots of high-fat, salty or sugary foods. This information could then be used to promote healthier alternatives.
Other suggestions included using more fruit and vegetables in ads, and placing healthy snacks rather than confectionery at checkouts.
Rival supermarket chain Asda, which is the second-largest after Tesco, has agreed to place fresh fruit instead of sweets at checkouts to help parents resist the demands from children for confectionery.
Head of Asda's non-branded products Penny Coates told the health select committee that from the New Year all 265 Asda stores will place portions of fruit and other healthy snacks at checkouts, but initially only at three in 20 checkouts.
Tesco's North rejected the suggestions that the loyalty card could be used to target unhealthy eaters, saying that it would be inappropriate and saying that some customers might think it was patronising or draconian.
On this point Asda's Coates agreed with North, denying that stores had a moral duty to encourage better eating habits among their customers.
Pressure groups are calling for a ban on the advertising of junk food to children in the UK, but the advertising industry has rejected the call. It says that the government should spend more money advertising healthy lifestyles.
In the US, Senator Joe Lieberman, who was Al Gore's running mate in the 2000 presidential election, has called for the Federal Trade Commission to investigate the marketing of junk food to American children.
He said that big food companies targeting junk food at children was "feeding an epidemic of obesity". Among his proposals are making food companies clearly mark the nutritional content of food on menus and on packaging, and developing standards for the food that is sold in schools.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the Forum here.