'Fat police' plan to screen all pupils criticised by watchdog

The plan to tell parents the test results - first disclosed by this newspaper - has provoked a furious Whitehall row between the Department of Health and the head of the official children's watchdog.

The Children's Commissioner, Professor Al Aynsley-Green, is concerned that telling parents their children's body mass index (BMI) risks stigmatising larger pupils.

A statement from his office makes clear that he has grave doubts about whether the measure can help children get back into shape.

"BMI is not a reliable indicator of obesity in children. It is a very crude measurement which just takes the child's weight and adjusts it to take account of how tall the child is."

The statement adds: "The risk is that using it as an individual measurement tool could lead to parents being provided with an inaccurate and confusing picture [of no] benefit to the child."

But Caroline Flint, the health minister, remains determined that parents of children whose BMI suggests they may be obese should be told.

Intended to provide a "fat map" of children's obesity, the data collection exercise looks to be in trouble already, as a number of primary care trusts admit that they are unlikely to take the measurements this summer term as intended.