The average 10-year-old has consumed as much sugar in their lifetime as the recommended limit for an 18-year-old, according to Public Health England (PHE), which is warning of serious implications for obesity and health.

Children are consuming the equivalent of eight excess sugar cubes a day, or 2,800 a year, says PHE, which has launched a new healthy eating campaign under its Change4Life scheme. National guidance recommends no more than five or six sugar cubes (20g-24g) a day for children aged four to 10.

One-third of children are overweight or obese at the age of 10 and 4.2% are severely obese in year six at school. Obese children often become obese adults, at risk of heart attacks, strokes and type 2 diabetes.

The healthy eating campaign will urge parents to cut the amount of sugar in their families’ diet by switching to lower-sugar drinks, cereals and yoghurts. PHE attempts to persuade the food industry to reformulate the products available in supermarkets have had limited success.

The organisation had called for a 20% reduction in sugar content by 2020, and a 5% cut in the first year, ending April 2018, but a report in May said manufacturers and supermarkets had managed only 2%. Yoghurts, breakfast cereals and sweet spreads were the only food groups to achieve a 5% reduction.

The campaign emphasises breakfast cereals and yoghurts, together with sugary drinks, where reformulation is happening because of the sugar tax. But not all products in those categories have had their sugar content lowered.

PHE wants families to switch to those that have, and it rewarded some of the companies that have made significant sugar cuts with a mention. Nestlé Shredded Wheat, Nestlé Low Sugar Oat Cheerios, Petits Filous and Soreen malt loaf are some of the brands that will carry a Change4Life “good choice” badge in shops.

“Children are consuming too much sugar, but parents can take action now to prevent this building up over the years,” said Dr Alison Tedstone, PHE’s chief nutritionist. “To make this easier for busy families, Change4Life is offering a straightforward solution – by making simple swaps each day, children can have healthier versions of everyday foods and drinks, while significantly reducing their sugar intake.”

The Obesity Health Alliance, an umbrella group that includes charities and medical organisations, said more urgent action than messages on swapping high-sugar foods for low-sugar alternatives was needed.

“Today’s children are growing up in obesogenic environments, bombarded by adverts and promotions for junk food online, on TV and in our supermarkets,” said Caroline Cerny, the alliance lead.

“Government proposals to restrict junk-food marketing, tackle price- and place-based promotions and ensure calorie labelling in cafes and restaurants will, if fully implemented, make progress towards reversing our current worrying obesity trends. But the food industry must also do their bit, cutting sugar levels from their products in line with government’s reformulation programme. It is only through concerted action at all levels that we can ensure a healthier future for this country’s children.”

PHE wants families to choose lower-sugar yoghurts (cutting six cubes to three), swap sugary drinks for no added-sugar drinks (two cubes to half a cube) and frosted or chocolate cereal for something lower in sugar (three cubes to half a cube per bowl). This could cut a child’s sugar intake by 2,500 cubes a year, it says.

Swapping chocolate, puddings, sweets, cakes and pastries for healthier options such as malt loaf, sugar-free jellies, lower-sugar custards and rice puddings would reduce their intake further, the organisation says.

Kawther Hashem, a researcher at Action on Sugar based at Queen Mary University of London, said: “Encouraging parents to halve their children’s sugar intake from everyday food and drink products is applaudable and we fully support the campaign.

“However, if we are to curb the UK’s escalating childhood obesity epidemic then the government must enforce more hard-hitting tactics such as mandatory uniform coloured coded labelling on front of packs, product reformulation with a 50% reduction in sugar across all products, a tax on confectionery and ensure that only healthy products are marketed and advertised.”