Children have already consumed more than the recommended intake of sugar for the whole of 2018, according to Public Health England.
The health authority says children aged four to 10 years are eating twice as much sugar as they should, averaging the equivalent of 13 sugar cubes a day.
This means they are on track to consume around 4,800 cubes of sugar by the end of the year, more than double the recommended maximum.
Health advisors say soft drinks are one of the main sources of sugar in children’s diets, accounting for more than ice cream and puddings combined.
They warn that too much sugar can lead to weight gain, obesity and tooth decay.
Official figures show a third of children leave primary school overweight or obese and a quarter of five year-olds suffer from tooth decay.
Dr Alison Tedstone, chief nutritionist at PHE said: 'We’re barely halfway through the year and already children have consumed far more sugar than is healthy – it’s no surprise this is contributing to an obesity crisis.
'Snacks and drinks are adding unnecessary sugar to children’s diets without us even noticing.
'Swapping to lower or no added sugar alternatives is something all parents can work towards.'
