"The food industry will do everything in their power to undermine this," he said.
The guidance suggests lowering the amount of sugar added to food - excluding that which occurs naturally in fruit or starch - from 10 per cent to five per cent of the daily allowance, which is equivalent to five teaspoons. The policy would almost certainly be adopted by the Department of Health.
Professor Shrinath Reddy, a cardiologist at the Harvard School of Public Health and member of the WHO panel of experts, said: "I would agree with the recommendation to reduce it to five per cent.
"There is overwhelming evidence coming out about sugar-sweetened beverages and other sugar consumption links to obesity, diabetes and even cardiovascular disease."
The proposals were discussed at a meeting earlier this year after a study by Professor Paula Moynihan, an expert in nutrition and oral health at Newcastle University, highlighted the danger of sugar to dental health.
"Part of the problem is that sugary foods and drinks are now staples in many people's diet in industrialised countries, whereas once they were an occasional treat," he said. "We need to reverse this trend."
The WHO panel will consider the guidance over the coming months before making a final decision.
Sugar Nutrition UK, an industry-funded research body, pointed out that UK manufacturers had been lowering the level of sugar in recent years to make products healthier.
"There is no data to show that reducing intake below current levels is beneficial to health," said a spokesman, who claimed that the guidance was based on studies "of very low quality".
Research three years ago by the Emory School of Medicine in the US found that some adults were eating 46 teaspoons of sugar a day. This included six in a bowl of cereal, 14 for lunch including a slice of pizza and a fizzy drink, and 16 for a ready meal in the evening with another sugary beverage.
Kellogg's was criticised last year by the Advertising Standards Agency for claiming that high sugar was not linked to obesity.
Its Coco Pops website claimed: "A panel of world health experts recently reviewed all the evidence and concluded that a high sugar intake is not related to obesity, or the development of diseases such as heart disease, diabetes, high blood pressure or cancer. Nor was it connected to behavioural problems, such as hyperactivity, in children."
- Daily Mail