Obesity crisis in schools: How one child in three is too fat by the age of 11NHS data reveals 19 per cent of Year 6 children obeseLondon has highest proportion of obese childrenObesity more common in towns and cities than rural areas

Obesity is also more common in towns and cities than rural areas, according to newly-released data

Obesity is also more common in towns and cities than rural areas, according to newly-released data

One child in three is overweight when they leave primary school at the age of 11, alarming figures reveal.

Almost a fifth are classed as obese, meaning they are so fat they risk knocking years off their lives.

And the number of ten and 11-year-olds who fall into this category has risen by nearly 10 per cent in just four years, according to NHS data.

In some towns and boroughs, more than a quarter of children this age are obese.

Experts warn that many of these youngsters will stay fat for the rest of their lives, putting them at greater risk of heart disease, diabetes and other serious illnesses.

The figures show 33.4 per cent of children in Year 6, the final year of primary school, are overweight or obese.

This is up from 31.6 per cent in 2006/7, the first year when the data was collected.

But there is mounting concern that the Government is not doing enough to tackle the nation’s weight problem.

Earlier this year Health Secretary Andrew Lansley’s 54-page obesity strategy was condemned as ‘woefully inadequate’ by medical experts.

Labour public health spokesman Diane Abbott said: ‘The entire strategy can, shockingly, be summed up in two words: eat less.’

The fattest... and thinnest

Tracy Parker, dietician at the British Heart Foundation, warned: ‘Obese children are more likely to become obese adults. And obesity in adults is associated with an increased risk of type two diabetes and heart disease.’

The figures come from more than a million children who are part of the National Child Measurement Program, which records their weight and height in the first and last years of primary school.

Based on this information it is possible to calculate their Body Mass Index, which is an estimate of their body fat.

Children are classified as obese if their BMI is high for their age. There is a slightly different limit for each age group above which a child would be considered obese.