This thread has caused me to recall my own childhood - yes, I was a fat child.
I remember a nurse turning up at our house one day, with no appointment or prior notice, and telling my mum I was overweight and would have to go on a diet. I think it was early on in secondary school. I had to see a dietician every month (I think) for ages - until taking time off school for appointments started to impinge on my work.
I had to take my own lunch into school and was pretty much ridiculed by all around me. It seemed that being a fat kid on a diet was even funnier than just being a fat kid.
I lost weight, put up with a lot of teasing and unhappiness, then put all the bloody weight back on again. It was stressful, humiliating and utterly pointless.
My DD starts school in September. To read that she might be labelled too fat, too thin etc at this age makes me want to scream. And no, she's not overweight.