By the age of ten, British children are eating the recommended sugar allowance for an 18-year-old, according to a new report.
The claim comes from Public Health England (PHE) and is based on total sugar consumption from the age of two.
The government body said that while consumption has declined in recent years, children are still ingesting the equivalent of around eight sugar cubes per day. That adds up to 2,800 cubes per year.
The news came as severe obesity in 10 to 11-year-olds in the UK was at an all-time high.
PHE said overweight or obese children were more likely to carry the same condition into adulthood, increasing their risk of heart disease and some cancers. At the same time, more young British people than ever were developing type two diabetes.
The government also said excess sugar can lead to painful tooth decay, bullying and low self-esteem in childhood.
PHE urged parents to help tackle the problem and launched a new Change4life action campaign aimed at helping people break the sugar cycle.
The programme recommended making simple swaps each day so children can have healthier versions of everyday foods and drinks, while significantly reducing their sugar intake.