Switching to a plant-based diet can help fight climate change, UN experts have said.
A major report on land use and climate change says the West's high consumption of meat and dairy produce is fuelling global warming.
But scientists and officials stopped short of explicitly calling on everyone to become vegan or vegetarian.
They said that more people could be fed using less land if individuals cut down on eating meat.
The document, prepared by 107 scientists for the UN's Intergovernmental Panel on Climate Change (IPCC), says that if land is used more effectively, it can store more of the carbon emitted by humans.
It was finalised following discussions held here in Geneva, Switzerland.
"We're not telling people to stop eating meat. In some places people have no other choice. But it's obvious that in the West we're eating far too much," said Prof Pete Smith, an environmental scientist from Aberdeen University, UK.
The report calls for vigorous action to halt soil damage and desertification - both of which contribute to climate change.
It also warns that plans by some governments to grow trees and burn them to generate electricity will compete with food production unless carried out on a limited scale.
The Earth's land surface, and the way it is used, forms the basis for human society and the global economy.
But we are re-shaping it in dramatic ways, including through the release of greenhouse gases into the atmosphere. How the land responds to human-induced climate change is a vital concern for the future.
How are climate change and food linked?
Climate change poses a threat to the security of our food supply. Rising temperatures, increased rain and more extreme weather events will all have an impact on crops and livestock.
But food production also contributes to global warming. Agriculture - together with forestry - accounts for about a quarter of greenhouse gas emissions. Livestock rearing contributes to global warming through the methane gas the animals produce, but also via deforestation to expand pastures, for example.
The environmental impact of meat production is important to many vegetarians and vegans. A UK-based group called #NoBeef lobbies caterers to take beef and lamb off student menus.
In the US, vegan burger patties are made from plant-based meat substitutes said to taste like the real thing thanks to an iron-rich compound called heme.
Peter Stevenson, from Compassion in World Farming, said: "A reduction in meat consumption is essential if we are to meet climate targets".
But in some parts of the world, such as China, beef consumption is growing. This is despite attempts by the Chinese central government to promote traditional diets.
The authors of the report encourage action to stop wasting food - either before or after its sale to consumers.
Waste food can sometimes be used as animal feed or, if suitable, redirected to charities to feed people in need.
One organisation in Switzerland called Partage takes in unsold food discarded by shops and distributes it to local families.
It also collects stale bread and turns it into biscuits, dries fruit, and cans vegetables. All of this helps reduce the CO2 emissions involved in producing food.