Introduction of the "sugar tax" in the UK led to a significant reduction of daily sugar intake by around 5 g in children and by around 11 g in adults, revealed a study on Wednesday.

More than 50 countries have introduced a sugar tax on soft drinks to persuade manufacturers to reformulate their products. In the UK, the sugar tax, also known as the soft drinks industry levy, was announced in March 2016 and came into effect in April 2018.

Researchers from the universities of Cambridge, Bath, and Oxford analysed 11 years of data involving 7,999 adults and 7,656 children from the UK National Diet and Nutrition Survey.

The results, published online in the Journal of Epidemiology and Community Health, showed that one year after the UK sugar tax had come into force, children further reduced their free sugar intake from food and drink combined by around 5 g per day (relative reduction of 10 per cent) and adults by around 11 g per day (a relative reduction of 20 per cent).

Over half of this total was from soft drinks alone -- accounting for around 3 g per day (relative reduction of 23.5 per cent) in children and around 5 g per day (relative reduction of just under 40.5 per cent) in adults.

Protein intake remained stable throughout in children and adults.

"In children, a daily reduction of 4.8 g sugar equates to approximately 19.2 kilocalories out of an approximate daily intake of 2,000 kilocalories, which is equivalent to approximately 1 per cent reduction in energy intake," pointed out the researchers.

There is ample evidence to suggest that consumption of sugar-sweetened drinks -- a major source of dietary free sugars, particularly among children -- results in a heightened risk of weight gain, type 2 diabetes, coronary heart disease, and premature death.

However, the overall daily energy intake from free sugar levels was still higher than the updated recommendation from the World Health Organization (WHO) of 5 per cent -- equivalent to 30 g/day for adults, 24 g for 7-10-year-olds, and 19 g for 4-6-year-olds, said the researchers.