Prime Minister David Cameron says he does not want to rule out introducing a sugar tax in order to tackle Britain's "obesity crisis".
Mr Cameron said it would be better not to have to resort to new taxes but said that "what matters is we do make progress" on obesity.
The PM was speaking to journalists following reports a tax on sugary drinks was being considered.
Number 10 previously said he "doesn't see a need for a tax on sugar".
In October a report by Public Health England recommended a tax of between 10 and 20% on high-sugar products as one of the measures needed to achieve a "meaningful" reduction in sugar consumption.
Celebrity chef Jamie Oliver has also campaigned for such a move, while a new study in the British Medical Journal said Mexico's sugary drinks tax led to a 12% reduction in sales.
Asked at a press conference in Hungary whether he was ready to reverse his previous opposition to the policy, Mr Cameron said: "I don't really want to put new taxes onto anything but we do have to recognise that we face potentially in Britain something of an obesity crisis when we look at the effect of obesity on not just diabetes but the effect on heart disease, potentially on cancer."
The PM said the government would come up with a "fully worked-up programme" to tackle obesity, with details announced later this year.
He added: "We shouldn't be in the business of ruling things out but obviously putting extra taxes on things is not something I aim to do, it's something I would rather avoid."
A Downing Street spokeswoman said more needed to be done to reduce obesity and urged the food and drink industry to develop more alternative products that do not have high sugar levels.
The Food and Drink Federation has said it does not agree evidence supports the introduction of a tax on sugary products and that industry is "determined" to help tackle childhood obesity.