HEALTH warnings should be added to sugary drinks in an attempt to make them as socially unacceptable as cigarettes, a leading figure in public health has said.

Professor Simon Capewell, professor of public health at the University of Liverpool, called for the UK Government to follow the example of legislation under consideration in California proposing warnings to consumers about the contribution of fizzy drinks to obesity, diabetes and tooth decay.

In an personal view published on bmj.com, Prof Capewell said a third of children and two-thirds of adults are now overweight or obese in the UK.

Halving US and UK children's sugar-sweetened beverage consumption could mean a 50 to 100 kcal reduction in energy intake a day, perhaps arresting or even reversing the current increases in obesity, he said.

He highlighted a recent European study showing adults who drank more than one can of sugary fizzy drinks a day had a 22% higher risk of developing Type 2 diabetes than those who drank less than a can a month.

He said there was public support for warnings about added sugar as the food stuff was being "progressively demonised".

"Many other potentially harmful products already carry effective health warnings. For example, insecticides and other toxic products have long carried labels warning users to take extreme care," he said.

"Similarly, cigarettes have gone from being socially acceptable to quite unacceptable after warning labels were implemented.

"The effectiveness of tobacco warnings and plain packaging is now accepted by almost everyone not linked to the industry."

Prof Capewell said warning labels represented an "interesting natural experiment" that "may offer an effective new strategy to complement existing, potentially powerful interventions like marketing bans and sugary drinks duties".

The call for labelling comes after research from the University of Glasgow was published earlier this year showing people are underestimating sugar levels in drinks which are perceived to be ''healthy'' options.

More than 2,000 people across the UK were asked to estimate how many teaspoons of sugar were in a variety of beverages.

While many overestimated the amount in fizzy drinks, they ''significantly misjudged'' the levels in milkshakes, smoothies and some fruit juices.

Gavin Partington, British Soft Drinks Association director general, said trying to blame one set of products for the "complex" problem of obesity was "misguided." He added that soft drinks have full nutrition labelling including calorie content printed on the pack.

"Obesity is a far more complex problem than Professor Capewell's simplistic approach implies and trying to blame one set of products is misguided, particularly when they comprise a mere 3% of calories in the average diet," he said.

"Soft drinks can be enjoyed as part of a balanced diet and all products have full nutrition labelling, including calorie content, printed on pack so consumers and parents can make informed choices about what they and their children are drinking.

"Manufacturers have been taking steps to reduce the calorie content of their drinks over many years - more than 60% of drinks now contain no added sugar.

"In addition, the leading producers and retailers with market share of around 75% are now signed up to the responsibility deal to reduce calories even more, backed by a significant increase in advertising and marketing expenditure on low and no calorie drinks."