Scientific advisers to the UK Department of Health have warned about the consequences of consuming too much sugar.
They would like the Government to instruct people of all ages to reduce the sugar in their diets and opt instead for fibrous foods, such as fruit, vegetables and wholegrain bread and cereals.
The recommendations come after a seven-year inquiry into ways to resolve the national epidemics of obesity and tooth decay.
Dr Ann Prentice, who chaired the study, said there was "strong evidence" that reducing sugar intake and eating more fibre lowered the risk of cardiovascular disease, type 2 diabetes and bowel cancer.
If the recommendations are implemented, it will be the first change to public guidance on sugar since 1991. The proposed limit of 25g for women and 35g for men is the equivalent of a single can of coca-cola with no other sugar content a day.
The five-a-day slogan could be replaced with eight-a-day for fruit and veg.
Adults could also be advised to raise significantly their fibre intake from 18g a day to 30g.
The British Nutrition Foundation, an academic charity funded by the food industry, worked out a weekly diet under the new regime. "No foods are banned in the model, but things like chocolate and fizzy drinks would have to be very occasional treats rather than something consumed daily, even if they were low-calorie versions," it said.
Fizzy drinks were out except for a very occasional low or zero calorie versions. No sugar in tea or coffee using only semi-skimmed milk.
In one week, there was just room for four squares of dark chocolate, two chocolate biscuits, and a small packet of crisps. Deserts were mostly fruit.
Healthy snacks included a handful of unsalted nuts and raisins one day and a plain scone with low-fat spread on another. Two glasses of wine were allowed during the week.
Many of the food alternatives to sugar would take many people over the Government’s target for salt.
"The models we created found the targets are achieved through a balanced, healthy diet - but it is one that looks very different from the diets we have today. We would love people to be eating as healthily as our model diet outlines, but we have to be honest and say there is a long way to go," a Foundation director said.
