Soaring child obesity rates are forcing food manufacturers to back away from TV advertising. So isn't it a trifle absurd that so many of the big guns are investing heavily in websites where children sit in front of a computer screen playing games instead? Bernice Hurst suspects bad faith.

The internet puts the lie to food companies' exhortations that children do not get fat from looking at advertisements or being influenced to eat vast quantities of their products but because they do not do enough exercise.

Just as manufacturers seem to be agreeing that the door to television advertising of junk food to kids should close, at least part way, the door to targeting children through websites is wedged firmly open.

As the executive director of New Zealand's Food Industry Group (FIG) recently said when disputing a report that food adverts contribute to obesity, it is "the sedentary activity of television watching" that is to blame.

While television watching is indisputably sedentary, so too is searching manufacturers' many brightly coloured links to mini-sites full of games and competitions. By its very nature, using the internet to promote products to children discourages exercise. How can they be outside playing games when they are inside playing games? How can they be running around or riding their bikes or doing anything physical when they're sitting in front of a computer?

Granted, other more active alternatives are sometimes proposed. The ill-fated Cadbury's Get Active campaign was a case in point. Encouraging children to collect vouchers for sports equipment by eating chocolate upset parents and teachers alike. Once the maths was done and it became clear how much chocolate needed to be consumed to earn a football, cries of horror drowned protestations that chocolate was not a bad thing to eat if it was an occasional treat and part of a balanced diet and a lifestyle that included plenty of exercise. Accusations of hypocrisy doomed the programme.

Interestingly, the countries with the highest levels of childhood obesity are English-speaking. Similarly, it is the English-language websites of multinational food manufacturers that contain most games. Kraft and Nabisco, for example, offer arcade games or, for those interested in being more active, albeit only vicariously, simulated sports games. There is no sign of anything aimed at children on any of their European, Russian or Ukrainian websites.

Nabisco World also directs kids to Kidnetic.com, described as "a cool site for kids…who like to play hard and have fun." Launched in 2002 as part of an "educational outreach programme" of the International Food Information Council (IFIC), it works with various American organisations to promote both healthy eating and physical activity. One way of achieving the latter is through the site's fitness challenge. Comprised of ten fun activities that involve getting up out of that chair in front of the computer, kids have to return after completing each task to start the next and keep the clock running. The challenge is to do the tasks in the shortest possible time. This constitutes an interesting compromise between active and inactive and perhaps suggests a way forward for other websites.

The list goes on. While television advertising is under the microscope, little attention is paid to the equally insidious temptation to avoid exercise presented by games and competitions that cannot even be found without camping in front of a computer. Encouraging children to lead a solitary and sedentary life in front of a computer screen is the door left open when the more widely publicised door to television screens is slowly closing.