Switching red meat and dairy for beans, chicken and vegetables are not only healthier but more environmentally friendly too, suggests new research.
But scientists say you don’t have to go vegan to be green as you can have the occasional steak or piece of blue cheese and still do your bit.
Just a moderate shift away from red meat, diary and high calorie foods all goes to helping save the planet and our health.
The study looked at the carbon footprint of what more than 16,000 Americans ate in a day by comparing foods to the amount of greenhouse gas emissions.
It was the first to compare the climate impact and nutritional value of US diets using real-world data about what Americans say they are eating.
Even a slight shift away from red meat, diary and high calorie foods all goes to helping save the planet and our health, scientists at Tulane University said
Professor Diego Rose, of Tulane University, said: ‘People whose diets had a lower carbon footprint were eating less red meat and dairy – which contribute to a larger share of greenhouse gas emissions and are high in saturated fat – and consuming more healthful foods like poultry, whole grains and plant-based proteins.’
He added they hoped the finding will help the public and policymakers recognize that improving diet quality can also help the environment.
Dr Rose said: ‘We can have both. We can have healthier diets and reduce our food-related emissions.
‘And it doesn’t require the extreme of eliminating foods entirely.
‘For example, if we reduce the amount of red meat in our diets, and replace it with other protein foods such as chicken, eggs, or beans, we could reduce our carbon footprint and improve our health at the same time.’
Research Specialist Martin Heller at the University of Michigan, Ann Arbor, added: ‘The good news here is that there are win-win solutions with diets that are healthier for people and planet.
‘Big reductions in food-related emissions don’t require eliminating foods entirely: moderate shifts away from red meat and toward beans, eggs or chicken can lead to significant improvements in both health and our diet’s carbon footprint.’
The study built an extensive database of the greenhouse gas emissions related to the production of foods and linked it to a large federal survey that asked people what they ate over a 24-hour period.
Researchers ranked diets by the amount of greenhouse gas emissions per 1,000 calories consumed and divided them into five equal groups.
Then they rated the nutritional value of foods consumed in each diet using the US Healthy Eating Index, a federal measure of diet quality, and compared the lowest to the highest-impact groups on this and other measures.
Overall, diets in the lowest-impact group were healthier, but not on all measures.
However, these diets also contained more of some low-emission items that aren’t healthy, namely added sugars and refined grains.
They also had lower amounts of important nutrients, such as iron, calcium and vitamin D, likely because of the lower intakes of meat and dairy.
Dr Rose added this was because diets are complex with many ingredients that each influence nutritional quality and environmental impacts.
He said: ‘This explains the nuanced relationship we observed between these outcomes.’
Diets in the highest-impact group accounted for five times the emissions of those in the lowest-impact group.
The highest-impact diets had greater quantities of meat such as beef, veal, pork and game, dairy and solid fats per 1,000 calories than the low-impact diets.
Overall, the high-impact diets were more concentrated in total proteins and animal protein foods.
A previous study by the researchers released last year found that 20 percent of Americans accounted for almost half of US diet-related greenhouse gas emissions.
The study was published in the American Journal of Clinical Nutrition.