No restaurants ask you to carbon offset your dinner, but there's a new guide to determine your meal's greenhouse gas emissions.
Researchers from RMIT University collaborated with Lancaster University to come up with a comprehensive list of common foods and their corresponding greenhouse gas emissions needed to grow and process it.
Researchers found grains, fruit and vegetables had the lowest impact, then nuts and pulses.
As for protein, eggs, chicken, pork and most fish had a medium impact while beef and lamb had the highest impact.
On average, 1kg of greenhouse gas emissions is equal to:
1.2kg of peanuts
800ml of milk
290g of salmon
five small eggs
270g of chicken
244g of kangaroo
212g of rabbit
131g of Australian pork
57g of Australian lamb
44g of Australian beef
Researcher Stephen Clune said beef and lamb did not score well because they were ruminant animals with multiple guts.
"You would have a hard time arguing that you can replace beef with onions as they serve very different culinary and dietary requirements," Clune said in a statement.
"However, it is possible to substitute red meat with other meats, or plant-based protein sources such as lentils and nuts that have a lower impact.
"Our results could be used with confidence to plan menus for individuals and catering companies who want to reduce their carbon footprint, by selecting foods from different categories."