Food companies could be forced to pay a ‘sugar tax’ if they continue to sell unhealthy food, a Government minister has warned.

Speaking at the Hay Festival, George Freeman, Life Sciences Minister, said sweet drinks and other sugar-rich foods were making Britain’s obesity crisis worse. About 25 per cent of adults are obese, compared to just three per cent 40 years ago.

Mr Freeman said that he did not think that “heavy-handed legislation is the way to go,” The Daily Telegraph reported.

However he added: “I think that where there is a commercial product which confers costs on all of us as a society, as in sugar, and where we can clearly show that the use of that leads to huge pressures on social costs, then we could be looking at recouping some of that through taxation.

“Companies should know that if you insist on selling those products, we will tax them.”

Professor Tim Lang, an expert on food policy at City University London, said some companies were producing food so unhealthy that it was unworthy of the name.

“They should not be allowed to call unhealthy food 'food’. It should only be allowed to be called 'snacks,’” he told an audience at the festival.

“They are basically just using a raw food ingredient to wrap sugar and flavourings around.”

Katherine Jenner, campaign director of pressure group Action on Sugar, said Britons needed to be weaned off their addiction to sugar.

“We have become a nation hooked on the white stuff, expecting all our food and drink to taste incredibly sweet,” she said.

“If we can slowly and gradually reduce the sugar and the sweetness as we have already done for salt we can all get used to far less sugar.”

Tesco has become the first supermarket to pledge to reduce the sugar content of all of its drinks with the amount to be reduced by five per cent a year for the foreseeable future.

The Department of Health said it was not planning to introduce a sugar tax, but a review of the idea is being carried out by Teesside University for Public Health England.

Mr Freeman’s remarks will be seen as an attempt to persuade food companies to clean up their act.