THE FEDERAL TRADE COMMISSION has now agreed to consider imposing major restrictions on television advertisments aimed at young children. The primary goal of the proposal is to reduce the amount of sugar children eat. Few people, least of all thoughtful parents, will disapprove of that goal. But the means the FCC is considering are something else. It is a preposterous intervention that would turn the agency into a great national nanny.

The proposal has three parts (or "options," as the staff naturally describes them): A complete ban on advertising on programs aimed at children under 8 years of age; a ban on all ads on programs aimed at children under 12 for those sugar-coated products most likely to cause tooth decay; and a requirement that if ads for other heavily sugared products appear on programs aimed at children under 12, such ads be balanced by separate dental and nutritional ads.

Now, it is true that children watch many hours of television and see thousands of advertisments that cause them to demand that their parents buy certain products, mostly candy and cereals with huge amounts of sugar in them. And parents often yield to those demands, with the result that children eat more sugar than is good for them - from which the FTC's staff concluded that government must do something about the ads to protect the children.

But what are the children to be protected from? The candy and sugar-coated cereals that lead to tooth decay? Or the inability or refusal of their parents to say no? The food products will still be there, sitting on the shelves of the local supermarkets after all, no matter what happens to the commercials. So the proposal, in reality, is designed to protect children from the weakness of their parents - and the parents from the wailing insistence of their children. That, traditionally, is one of the roles of a governess - if you can afford one. It is not a proper role of government. The government has enough problems with television's emphasis on violence and sex and its shortages of local programing, without getting into this business, too.

The government can try to warn children (and parents) about the dangers of eating too much sugar. It has been doing so for generations and it might as well keep trying. If a case can be made, warning labels can be required and limitations on the amount of sugar added to foodstuffs can be imposed. Television stations can be encouraged - perhaps even required - to carry dental health ads during children's programs.

But a flat ban on commercials involving, as it would have to, cartain judgements a government shouldn't be encouraged to make a enforce, would make parents less responsible, not more.