More than one in three children in parts of Lancashire leave primary school obese or overweight, according to research.
In Preston, 30 per cent of Year 6 children fall into one of the two categories, while a total of 26,400 youngsters in the North West leave school either obese or overweight.
The figures include 30 per cent of children in South Ribble, 32 per cent in Chorley, 35 per cent in Wyre and 31 per cent in Lancaster, as well as about 34 per cent across the region.
The British Heart Foundation (BHF) is now calling for a ban on all junk food TV advertising before 9pm, as part of the Government’s Childhood Obesity Strategy, to help improve children’s health.
They say millions of children across the UK are being exposed to junk food adverts during popular shows.
Analysis by the BHF shows weak regulations are creating loopholes that mean food companies can advertise junk food during programmes watched by children.
Current regulations mean foods high in fat, saturated fat, salt and sugar are banned from being advertised during children’s programming.
But the latest Ofcom figures show that 65 per cent of children watch TV during what is considered adult airtime.
Mike Hobday, director of policy at the BHF, said: “It’s worrying that so many children in the North West are obese or overweight. Carrying excess weight into adulthood increases the risk of developing heart disease in later life.
“We must not allow food companies to continue to exploit a failing regulatory system that allows them to bombard TV screens with junk food adverts at the times when the highest numbers of children are watching TV.”