Regional health board association GGD and Amsterdam’s VU university are calling for a “smart sugar tax” following an investigation showing excessive consumption of sugary drinks by Dutch teenagers.

The average consumption by youngsters aged 12 to 16 is  9.5 glasses of sugary drinks a week but half consume as many as 16.5, the equivalent of 90 sugar cubes.

The figures are “alarming”, researchers said. “I was a bit taken aback by the results,” health scientist and researcher Rianne Pepping told broadcaster NOS. “The bigger the sugar intake, the bigger the risk of becoming overweight and developing type 2 diabetes,” she said.

Some 400,000 children in the Netherlands are overweight, 25% of whom are classed as obese.

The teens on 90 sugar cubes a week are exceeding the maximum consumption recommended by the World Health Organisation (WHO) which, for example, is 44 cubes for 12-year-old girls with a moderately active lifestyle and 79 for 16-year-old boys with a very active lifestyle.

Sugary drinks include fruit juice, fizzy drinks, cordials, iced tea, sports drinks and energy drinks. “All drinks containing sugar but which have no nutritional value, really,” Pepping said.

The investigation also showed that most teenagers would not buy the drinks, which were purchased mainly in supermarkets, if they cost more than €3 for a small can.

The new government is planning to introduce a sugar tax by 2030 but this should be brought forward, the researchers say. This would prompt both drinks manufacturers to limit the amount of sugar and encourage teenagers to make healthier choices.