Meanwhile, Nestle and Unilever ranked highest for their policies on seven areas assessed by Oxfam as critical to sustainable agriculture: women, small-scale farmers, farm workers, water, land, climate change and transparency.
Oxfam said in the report that Nestle and Unilever had done more to tackle social and environmental risks within their supply chains than companies it ranked less favourably including AB Foods and Kellogg Co.
Big food and beverage companies have come under increasing scrutiny in recent years over their sourcing of raw materials, courting criticism on issues ranging from child labour on cocoa farms to the impact of palm oil plantations on rain forests.
Oxfam said it had launched the "Behind the Brands" campaign to try to assess "ubiquitous" declarations of sustainability made by food and beverage companies as well as a proliferation of corporate social responsibility programmes.
"There are enormous gaps in terms of basic transparency which makes it very difficult to hold these companies to account," Raymond Offenheiser, President of Oxfam America, told a phone conference for journalists.
"The goal is not to criticise these companies for poor performance but encourage a 'race to the top'."
Oxfam ranked Nestle first, Unilever second, Coca-Cola third, PepsiCo fourth, Mars fifth, Danone and Mondelez International joint sixth, Kellogg Co and General Mills join eighth, and AB Foods in 10th place.