Britain's obesity "crisis" must be tackled as seriously as smoking, David Cameron said in a strong hint that a tax could be imposed on sugary drinks.
The Prime Minister said he remained reluctant to take the radical step but recognised the need to act to prevent increases in diabetes and cancer and cut the costs to the NHS.
A new anti-obesity strategy is due to be published by the Government within weeks.
Celebrity chef Jamie Oliver has been spearheading a campaign in favour of increasing prices and a report from Public Health England concluded a tax of 10% to 20% could work.
A study published in the British Medical Journal (BMJ) also shows that a sugary drinks tax in Mexico has led to a 12% reduction in sales and a 4% increase in the purchase of untaxed drinks one year after it came in.
Cancer Research UK has called for a tax on sugary drinks for the first time in a bid to curb rising rates of cancer caused by people being overweight.
Asked if he was ready to reverse his previous opposition to the policy, Mr Cameron said: "Of course it would be far better if we could make progress on all these issues without having to resort to taxes. That would be my intention.
"But what matters is that we do make progress.
"We need to look at this in the same way in the past we have looked at the dangers of smoking to health and other health-related issues.
"So that is my commitment: we need a fully-worked up strategy, we shouldn't be in the business of ruling things out but obviously putting extra taxes on things is not something I would aim to do, it is something I would rather avoid."
Speaking during a press conference in Hungary where he held talks with counterpart Viktor Orban, he told reporters: "I don't really want to put new taxes on 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 not just on diabetes but the effect on heart disease, potentially on cancer, when we look at the costs on the NHS, the life-shortening potential of these problems.
"We do need to have a fully-worked-up programme to deal with this problem and address these issues in Britain and we will be making announcements later in the year."