People will be advised to halve the amount of sugar in their diet, under new World Health Organisation guidance.

The recommended sugar intake will stay at below 10 per cent of total calorie intake a day, with 5 per cent the target, says the WHO.

The suggested limits apply to all sugars added to food, as well as sugar naturally present in honey, syrups, fruit juices and fruit concentrates.

UK campaigners say it is a tragedy that the WHO has taken 10 years to think about changing its advice. The recommendation that sugar should account for no more than 10 per cent of the calories in the diet, was passed in 2002.

It works out at about 50 grammes a day for an adult of normal weight, said the WHO.

However, experts now think 10 per cent is too high, amid rising obesity levels around the world. 

Announcing the new draft measures, the WHO said in a statement: "WHO’s current recommendation, from 2002, is that sugars should make up less than 10 per cent of total energy intake per day. 

"The new draft guideline also proposes that sugars should be less than 10 per cent of total energy intake per day. 

"It further suggests that a reduction to below 5 per cent of total energy intake per day would have additional benefits.”

Dr Francesco Branca, WHO's nutrition director, told a news conference that the 10 per cent target was a "strong recommendation” while the 5 per cent target was conditional, based on current evidence.

"We should aim for 5 per cent if we can,” he added.

The plans will now go for public consultation, with firm recommendations expected this summer.

Public Health England said its scientific advisory committee on nutrition was reviewing evidence on sugar in the UK diet.

Director of Nutrition and Diet, Alison Tedstone, said: "Our surveys show that the UK population should reduce their sugar intake as average intake for adults is 11.6 per cent and for children is 15.2 per cent, which is above the current UK recommendation of 10 per cent.”

Campaign group, Action for Sugar, said it was pressing for 5 per cent to become the firm recommendation.

Nutritionist, Katharine Jenner, said: "It is a tragedy that it has taken 10 years for the WHO to think about changing their recommendation on sugar, which will have had astronomic implications on the millions affected by obesity and type 2 diabetes the world over.”

Basis for guidelines 

The WHO guidelines are based on a review of scientific evidence on the health impact of sugar, including damage to teeth and the effect on obesity.

The obesity study, published last year in the BMJ, found while sugar did not directly cause obesity, those who consumed a lot of it, particularly in sweetened drinks, tended to put on weight as sugary food did not make them feel full.