When children leave primary school more than 30 per cent of them are suffering from obesity, figures from the NHS Information Centre suggest.
During the 2008-2009 academic year around 90 per cent of children were weighed, with 31 per cent of girls and 35 per cent of boys found to have weight problems in their last year of primary school.
The figures suggest government attempts to reduce child obesity in schools from Luton to Leeds and London are not working and could support the argument that providing healthier school meals is more important than ever before.
Tim Straughan, chief executive of the NHS Information Centre, said: "These findings highlight the scale of obesity among some of our young children - something which may affect their future health."
In reality, the actual obesity figure could be higher than the study found, as there are likely to be many children with weight problems whose parents made sure they did not participate in the survey.
The School Food Trust has said academic performances can be boosted with free school meals.
Posted by Theo Foulds.