Oxfam said the amount of food that is wasted when one billion people go to bed hungry at night "is nothing short of a scandal."
Oxfam's head of economic justice policy Hannah Stoddart said: "It is a damning indictment of a food system that places greater importance on corporate profits than ensuring everyone has enough to eat.
"It's great news that the biggest supermarket in Britain is taking tentative steps to tackle the problem, but we need urgent action like greater regulation and investment from governments worldwide to fix the system."
Oxfam has said it is "appalled" that the number of Syrian refugees has reached two million, adding that the humanitarian response is "stretched to the limit".
Enough is enough. A generation of Syrians is paying too high a price in this conflict. They have been seriously let down by the international community, which has failed to prioritise a political solution to the conflict.
That must change. World leaders - especially President Obama and President Putin - must ensure the long-promised peace talks take place as soon as possible.
Oxfam's Director of UK Poverty, Chris Johnes, has warned that welfare reforms could tip even more people into food poverty:
These shocking figures show that a perfect storm of spiralling living costs, lack of decent, secure jobs and benefit changes are making it impossible for many people to feed themselves or their families.
It's clear there is a massive hole in the safety net when so many more people are being forced to rely on emergency food handouts.
We are worried this could be just the tip of the iceberg as changes to the welfare system already in the pipeline could rip apart the safety net with devastating consequences for those who rely on it.
Oxfam says that some 670,000 people have left Syria since the crisis began in March 2011 but numbers have risen recently. In Jordan alone, the number of people crossing daily trebled in the past week.
The cold weather has seen an increase in the number of those suffering respiratory infections and pneumonia, according to the aid agency, which is distributing mattresses, blankets, heaters and gas oil to help new arrivals.