It appears my wife and I have upset the Government, as part of the small minority of parents who refused to have our 11-year-old child weighed and measured in school last term. The authorities worry that it was the parents of fat children who opted out. Or it could have been parents like us, who object to being conscripted into a fat-headed crusade against child obesity that is heavy on political intrusion and light on proven effectiveness.

Letters are to be sent to parents whose children were weighed, giving a “mark” ranging from “underweight” through “healthy weight” to “very overweight”. There has been a predictable PC-gone-mad reaction to the Department of Health's predictably stupid decision to drop the word “obese”. But whatever words they use, the message is clear: that the authorities have the right to decide whether or not our children are living “healthy lives”. They want to measure not only body mass but moral worth, to decide whether our children fit the State's model. The most likely results will be to produce miserable kids and anxious parents.

Despite overegged talk of a child obesity “epidemic”, the real extent, causes and health consequences of children being overweight remain uncertain. What is more certain is the lack of hard evidence that campaigns of intervention in school or family life have any beneficial effects. But whatever the intentions, they do single out kids for more pressure, harassment and ridicule - which is all that our body-conscious pre-teens need.

Yet the authorities throw their substantial weight behind every stunt from policing lunchboxes to weighing children like little piggies. At a time when governments have lowered horizons from creating the Good Society to moulding the Healthy Citizen, the anti-obesity crusade legitimises public monitoring of private behaviour. Ours is an age when bullies can no longer call children fatty in the playground. Yet it is deemed legitimate for government to bully them and their parents, using obesity as a bogeyman in scary stories about how we are killing our kids.

It will be a joyless world for children if we turn the pleasures of food, drink and play into problems of “healthy living”. At the Museum of London yesterday, my daughters learnt about the statue Fat Boy of Pie Corner, erected where the Great Fire of 1666 ended to warn Londoners that it was caused by “the sin of gluttony”. Today the pious warn us about our unhealthy lifestyles rather than our sins. Back home, the children borrowed a neighbour's Wii Fit game. The first thing it does is decide whether you are ideal, overweight or obese. What fun!

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