Being a chubby child is no picnic - I know

Perhaps because I was a very fat toddler and the thought that I might have been weighed at school makes me want to howl. Imagine the before and after, the ostracising of children who already feel misfits. Remember there are five-year-olds already so full of self-loathing they cut themselves.

Then, although care is taken in the letter's language - the word "obese" is avoided - the diagnosis is dangerously simplistic and the warnings about future diseases like cancer and diabetes too horribly stark. And the initiative ignores cultural expectations, beauty myths, class and wealth.

At birth I weighed three-and-a-half pounds and looked, they say, like a blue-purple aubergine. My dad had vanished and we were poor. So mum borrowed cash to overfeed me on powdered milk, a mark of her love and unbroken pride. Soon I was a shuffling Miss Blobby with three chins. Among Asian and African families, if children are big it shows they are adored; a scrawny child symbolises neglect. After marriage, if an Asian couple doesn't steadily fatten up, rumours spread of marital unhappiness.

White working-class families, too, buy sweets, crisps and burgers as offerings of love for their children. On many estates most children are chubby and there is no stigma - and possibly fewer tortured anorexics, too.

Then there is the pernicious idea that anyone can get thin. Not true. Body type and cursed genes can thwart any diet. Only briefly was I a skinny latte, after my husband left, when I was ripped apart with grief.

I do believe in the nanny state. Good interventions stop citizens destroying themselves and their families. Laws prohibiting drink-driving, smoking in public spaces and speeding have helped protect countless reckless individuals. But this weight problem is more complex than ministers seem to understand.

Children whose families do not care about size need to lose weight, sure. But to push them into some systematised, official body size is reminiscent of Soviet communism - and will probably only make the fat rebel and down even more pop and chocs. Back to the drawing board, I say.