There has been an outbreak of childishness over the banning of junk food advertisements. Parts of the food industry are in a sulk, even though they have been given opportunity after opportunity to improve the nutritional quality of what they sell. The Grocer magazine is pouting about various anomalies in the way that food is classified, which will mean that diet colas can be advertised, but not Marmite. Programme makers are growling about the advertising revenue that they will lose. Ofcom, the broadcasting regulator, has picked its way through this minefield. But its own tone has been rather petulant and its ban regime contains some complexities that make it easy to be uneasy about regulation whose aims are, supposedly, laudable.

Three years ago, research by Ofcom found that advertising had a modest, direct effect on children’s food choices and a larger but unquantifiable effect on their food preferences. It was reasonable to conclude that targeted bans on advertising, starting with broadcasters, might help to produce modest improvements in child health. So from April, adverts for foods high in salt, fat or sugar will not be permitted to be shown during programmes aimed at children under 10. From January next year that ban will extend to programmes geared to the under16s. The bans will be phased in order to allow existing campaigns to run their course.

There is little doubt that food manufacturers have used some highly sophisticated marketing methods to lure children into eating food that is bad for their waistlines, their health and perhaps also their powers of concentration. The “beloved children’s characters” they have deployed in that cause have in some cases been created solely for that purpose.

But Ofcom’s answer to this problem is unnecessarily confusing. Advertisers will not be allowed to use celebrities who appeal to young people, nor licensed characters such as Winnie-the-Pooh. But they will be able to use manufacturers’ own characters, such as that breakfast-time staple Tony the Tiger, of Frosties fame. They will be able to advertise the brand (such as McDonald’s), but not always the product. They will be permitted to advertise during Coronation Street, but not during Friends, which has a higher proportion of young viewers. There is some junk logic here.

Ofcom’s “nutrient profiling model” is another problem. Supported by dietitians, this is supposed to sort the (high-fibre) wheat from the (saturated) chaff. But it has produced some absurdities, such as a ban on advertising raisins but not on promoting white bread. The Food Standards Agency says that the anomalies do not matter because the few healthy products that will be banned are not marketed to children. But this misses the point that regulation, if it is to be introduced, should be fair, transparent and rational.

Limiting adverts will, it is to be hoped, limit the attractiveness of bad food. It may even encourage manufacturers to reformulate their products. Yet the eating patterns of British children will not fundamentally change until parents and schools become more discriminating about food, and more robust about saying “no” to children. No regulator can be a real substitute for an Ofparent.

It is ironic that Ofcom believes that it has to use its taxpayer-funded “pester power” to protect parents from the pestering of their own offspring. Ofcom must use this power wisely, or risk becoming as overdemanding and puerile as the little blighters they seek to dissuade.