Mr Brown wants poorer countries to be given more help
Gordon Brown has pledged to examine the impact of biofuels on world food prices, at a meeting with aid agencies, scientists, supermarkets and farmers.
The prime minister said Britain had to be "selective" in supporting biofuels and change its approach if necessary.
Oxfam's Phil Bloomer welcomed the news, saying biofuels pushed up food prices and led to "land grabs" from the poor.
There are concerns that agricultural land is being used to produce biofuels despite a shortage of food production.
Aid agencies, farmers, supermarkets and scientists met the prime minister at Downing Street earlier for a meeting to discuss rocketing global food prices.
The government has pledged £30m towards the World Food Programme to help tackle the "food crisis", and says it wants more agricultural research to boost production in developing countries.
Mr Brown called for international action, saying global food prices were at their highest since 1945 and tackling hunger was "a moral challenge" for everyone.
And days after implementing the Renewable Transport Fuel Obligation, which requires petrol and diesel to contain a proportion of biofuels, Mr Brown acknowledged their impact on world food prices and the environment.
He said the UK needed to look closely at the impact and ensure "we are more selective in our support".
"If our UK review shows that we need to change our approach, we will also push for change in EU biofuels targets," he added.
Mr Bloomer said: "Setting mandatory targets for biofuels before we are aware of their full impact is madness.
"Not only are biofuels pushing up food prices, but they are also linked to human rights abuses and land-grabs from the poor." Friends of the Earth's food campaigner, Vicky Hird added: "UK and European targets for increasing bio fuel use by adding it to our petrol must be scrapped."
Writing for the Downing Street website earlier Mr Brown said that although British shopping bills had been forced up because of rising global food prices, the impact was felt hardest by the world's poorest countries.
"The World Health Organisation now views hunger as the number one threat to public health across the world, responsible for a third of child deaths and 10% of all disease," wrote Mr Brown.
"Tackling hunger is a moral challenge to each of us and it is also a threat to the political and economic stability of nations."
Groups attending Tuesday's meeting aim to come up with a plan to present to the EU and the G8 over the summer and a special meeting of the United Nations in September.
The World Bank says overall food prices have increased 83% in the last three years.
Earlier this month, it announced emergency measures, including a doubling of agricultural loans to African farmers, to tackle the problem.
It warned 100 million people in poor countries could be pushed deeper into poverty by spiralling prices.
The crisis has sparked recent food riots in several countries including Haiti and Egypt.