My nine-year-old, Adam, started the day with a cup of tea with four teaspoons of sugar in it. Then he had banana and yoghurt with a crust of golden syrup on top. After that, he made his Weetabix into a sugar barge, voyaging in a sea of milk: he ate the cargo and just a little bit of the boat.

After breakfast he went to the bathroom and brushed his teeth. Then he called for the sweetie jar and gobbled three humbugs and three mint imperials; he pondered a chewy cola bottle, rejected it, brushed his teeth again and went out to play with his cousins.

An hour later, the cousins were in hot tears because Adam had been boasting. He was allowed to have all the sweets he wanted, he told them; they still had to wait for Friday, sweetie day. Their mother, my sister, was not happy and she wanted it to stop. “But how's Adam behaving?” I asked her. “Oh, pretty normal - full of beans. Quite sweet, actually.” Ha ha.

Last month I promised in this column to carry out an experiment: to let my son have all the sugar he wanted (so long as he brushed his teeth). For one day. Like most parents, I was exhausted by the demands for sugar: the sneaky squirrelling away of it, the smuggling, the black markets and the surreptitious fingers in the sugar bowl.

The sugar hunger seemed to cause more rows than anything else, and led to more dishonesty. Could we not, with healthy, active children, just accept their need for basic carbs and let them satisfy it? So long, of course, as they brushed their teeth.

We consume amazing amounts of sugar today. In Scotland, where I live, we eat more of it than anywhere in the Western world, except the United States. Much of it is hidden in processed foods - breakfast cereals, biscuits, baked beans, even in what appear to be “natural” ready meals.

The Scottish food historian Maisie Steven has analysed the diet over two centuries. At the beginning of the period, rural working-class families would have eaten no sugar at all. In 1939, according to her research, a school-age child ate 105g a day. In 1982, it was 225g and today that figure is 425g. There is no maximum daily allowance for sugar, although the World Health Organisation recommends that it be no more than 10 per cent of a child's daily energy intake. For the average child in the rich world, it is about 30 per cent.

So what's wrong with it? The most sensible of the child nutritionists, Dr Alex Richardson, says that excessive sugar can lead to a variety of vaguely defined problems, including “foggy brain”, inability to concentrate, tiredness and nervousness. She says it will inhibit children's uptake of “good” carbs and other nutrients. It's addictive. And, of course, sugar can make them hyperactive.

Lots of you wrote to me. My mother-in-law suggested that we do blood-sugar tests on Adam, before and after. Some of you had come across the work of Beyond Chocolate (www.beyondchocolate.co.uk), which carries out interesting projects in schools in which children are offered biscuits or fruit during break - the choice is theirs. At first they all grab the biscuits, but after some days they relax. They realise that the biscuits aren't going to go away, and tend to balance them with fruit.

The consensus among those of you who wrote was striking: don't make sweets evil, avoid draconian bans, but rely instead on a child's intuitive sense of what his or her body needs. It seems to work.

What happened to Adam? He ate a good lunch that day and didn't want any ice-cream. His behaviour was, well, that of a normal nine-year-old boy. Later, at an agricultural show, he had some candyfloss. I offered him more. He said: “Dad, that's enough. I don't want to look like a junkie in your article. Unless you pay me.”

I'm not sure that my experiment proved anything other than Adam's sound good sense. I think, as ever, that in a world of myriad food scares, the best thing is to relax. And not react to every new horror that is reported. Better sweets, with no artificial colourings, are in the jar now. We are moving to honey rather than sugar on the Weetabix.

And, of course, we're brushing our teeth.

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