Food firms using fructose will be able to boast of health benefits despite fruit sugar being implicated in soaring US obesity levels

Obesity experts say they are appalled by an EU decision to allow a "health claim" for fructose, the sweetener implicated in the disastrous upsurge in weight in the US.

Fructose, the sugar found in fruit, is used in Coca-Cola, Pepsi and other sweetened US drinks. Many believe the use of high-fructose corn syrup caused obesity to rise faster in the US than elsewhere in the world. Europe has largely used cane and beet sugar instead.

But the EU has now ruled that food and drink manufacturers can claim their sweetened products are healthier if they replace more than 30% of the glucose and sucrose they contain with fructose.

The decision was taken on the advice of the European Food Safety Authority (Efsa), on the grounds that fructose has a lower glycaemic index (GI) – it does not cause as high and rapid a blood sugar spike as sucrose or glucose.

But, say obesity experts, fructose is metabolised differently from other sugars – it goes straight to the liver and unprocessed excess is stored there as fat, building up deposits that can cause life-threatening disease.

There is potential for products high in sugar including soft drinks, cereal bars and low-fat yoghurts to make health claims by using fructose. Lucozade Original contains 33g of sugar in a 380ml bottle, Sprite has 21.8g of sugar in 330ml cans and Dr Pepper 34.1g per 330ml.

Kellogg's Nutri-Grain Elevenses bars have 18g of sugar in a 45g bar – so are more than a third sugar.

Barry Popkin – distinguished professor in the department of public health at the University of North Carolina at Chapel Hill, in the US, who co-authored the groundbreaking paper linking high-fructose corn syrup to obesity in 2003 – said the ruling would lead to claims from food and drink firms that would mislead consumers.

"This claim is so narrow and it will confuse a whole lot of people," he said. "That's what the industry does an awful lot of. People see it and think, 'ah maybe it's healthy.'

"It brings into question the whole area of health claims. They are made on such short-term effects."

Drinking pomegranate juice might give you all the vitamin C and antioxidants you need that day, but six months of regular drinking could raise the risk of diabetes, he said.

A health claim relating to a lower glycaemic index ignored the wider and more important public health issue, he said: that we should all consume less fructose and other sugars.

George Bray, head of the division of clinical obesity and metabolism at the Pennington biomedical research centre in Louisiana and co-author of the fructose paper, said he could see no rational reason for adding pure fructose to the diet.

"Assuming that it is correct that manufacturers can substitute up to 30% fructose for glucose or sucrose, it would be a very sad commentary on their review of the literature," he said.

"The quantity of fructose appearing in the diet is already excessive in my view. [Focusing on the fact that] fructose does not raise glucose as much ignores all of the detrimental effects of fructose from whatever source."

Michael Goran, director of childhood obesity research at the University of Southern California, said that although it had a lower GI, "in the long term, excess fructose is more damaging metabolically for the body than other sugars".

He added: "This opens the door for the beverage and food industry to start replacing sucrose with fructose, which is presumably cheaper."

More people in Europe will be consuming more fructose as a result, he said. "This is a dangerous and problematic issue. There is going to be a big increase in fructose exposure."

The European Heart Network raised concerns with DG Sanco, the European commission's health department, and asked it to share its views with member states. Its director, Susanne Logstrup, warned that replacing glucose and sucrose with "healthier" fructose might make people think a drink or food was less fattening.

"If the replacement of glucose/sucrose is not isocaloric, replacement could lead to a higher caloric content. In the EU, the intake of sugar-sweetened beverages is generally too high and it would not be in the interest of public health if intake were to increase," she said.

Professor Mike Rayner, director of the British Heart Foundation health promotion research group at Oxford University and an adviser to the European Heart Network, said it was important the EU looked at nutritional health claims – and that it had in recent years taken a tougher stance.

"But here is an example in fructose of a claim that is technically probably true but has no public health benefit," he said.

Industry is delighted by the EU ruling. Galam Group, an Israeli fructose manufacturer, called the move "a game-changing step" in comments to the trade journal Nutra Ingredients. It said it expected a surge in sales from 2 January, when the ruling takes effect.