A committee of scientific experts is expected to urge the government to halve the recommended daily intake of sugar, in final guidance on Friday.
Government advisers in England are set to recommend that no more than 5% of daily calories should come from added sugar - about seven level teaspoons.
The guidelines are in line with new World Health Organization proposals.
According to existing research, all age groups in the UK consume at least twice this limit.
The Scientific Advisory Committee on Nutrition (SACN), which advises Public Health England and other government agencies on nutrition, is expected to call for the recommended daily intake of sugar to be halved to reduce obesity risk and improve dental health.
In a draft report last year, the committee said sugars should make up no more than 10% of energy intake and that people and governments should be aiming for 5%.
The main sources of refined sugars in the diet are sweetened drinks and cereal, confectionery, fruit juice and sugar added at the table.
A single can of fizzy drink contains about nine teaspoons of sugar.
It is one thing setting out what people should aspire to eat, quite another making it happen.
Achieving the expected threshold for added sugar - no more than 5% of calories consumed - will be a challenge for government, industry and the public.
At the moment, the average intake in all age groups is at least twice this limit.
The health arguments are compelling, but will people want to change their eating patterns, and will they be able to afford it?
The food industry says it is already working to cut added sugars.
Some health campaigners say clearer labelling will be needed so people can see at a glance how many teaspoons of sugar have gone into each portion.
The British Dental Association (BDA) has called on the government to take heed of the latest advice.
Tooth decay is the biggest cause of hospital admissions among young children.
Mick Armstrong, chairman of the BDA, said: "We have an historic opportunity here to end Britain's addiction to sugar.
"The government now has the evidence and a clear duty to send the strongest possible signal to the food industry that while added sugar might be helping their sales, it is hurting their customers."
The food industry has said calories in household foods and drinks have been gradually lowered in recent years, including sugar reductions and changes to portion sizes.
The guidelines refer to free sugars - those that are added to food by manufacturers or those naturally present in honey, syrups and unsweetened fruit juices.
According to health experts, 5% of daily energy intake is the equivalent of 19g or five sugar cubes for children aged four to six, 24g or six sugar cubes for children aged seven to 10, or seven sugar cubes for those aged 11 and over, based on average diets.
Sugar tax
Many health campaigners want to see a tax on sugar, with doctors' leaders joining the call this week.
The British Medical Association said a 20% levy on sugary drinks would be a step towards the long-term goal of taxing a wide range of products in the fight against obesity.
A review by Public Health England (PHE) on how these measures could be implemented is not expected until the end of the summer.
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