Our food system is broken. Not only do we eat too much junk that’s bad for us, but our food habits cause way too much deforestation and greenhouse gas emissions. Finding ways to tweak the food system and make it healthier and more sustainable is a major policy challenge for governments around the world. According to a new study, there’s a way to get the best of both worlds and encourage consumers to make healthier, greener choices. But there’s a catch: it uses a mechanism that’s traditionally very unpopular; a tax.

About a third of our greenhouse gas emissions come from the food we eat. Meat accounts for a disproportionate proportion of those emissions, especially red meat. Coincidentally or not, red meat is also bad for you, and research shows that regular consumption of red meat is bad for your health. So in one stroke, if people would reduce their consumption of red meat, their diets would become healthier and more sustainable.

But how do you people them to do this?

Combining the use of carbon and health taxes on food products is one way to go, according to a new study. Researchers found that applying a tax to products that have a high emissions footprint and are also bad for health would maximize the health and climate benefits.

In the UK, for instance, such a tax could reduce the annual greenhouse gas emissions by about 40 megatons of CO2 emissions — a third of what the country needs to do if it wants to reach net-zero emissions by 2050.

“To date, governments around the world have been at best hesitant to implement food taxes, with the focus of such tax incentives being mostly to deter the consumption of unhealthy foods to improve personal health and reduce pressures on health services,” Michaela Faccioli, one of the study authors, said in a statement.

Food and climate benefits

Food systems, from production to consumption, currently generate over a third of global greenhouse gas emissions, contributing to the climate crisis, while unhealthy diets account for one in five deaths globally. That’s why integrated policies that address climate and health aspects of the food system are of vital importance for global health and the climate crisis.

While supply-side initiatives are important, the scale and speed of the transformation needed to achieve health and climate targets require also considering demand-side shifts – from education to regulation and taxation. Some food taxes have been applied in recent years, seeking to improve people’s health through consumption changes.

The study looks at how food policies can alter the purchasing behavior of the public to tackle climate change and people’s diets at the same time. It’s based on a survey with about 6,000 UK respondents, created by a team from the University of Exeter, the University of Reading, and the London School of Hygiene & Tropical Medicine.

The respondents were given a list of common food and drink products, replicating the website of a supermarket, and were asked to indicate their typical weekly purchases. Then, subsequent questions showed the same range of products but with new prices or different product information to simulate the effect of food taxes and the provision of health and climate data.

Every time a new policy was introduced, such as a food tax, the respondents could review their food choices. The change in responses was used by the researchers to estimate the effect of the different policies on food purchase behavior and on greenhouse gas emissions and dietary quality. As it turns out, food taxes proved to be an efficient tool and should be something that policymakers strongly consider. In some cases, at least, taxes can actually be good for you.

“The addition of a carbon element to any food tax could create a win-win in which both health and environmental concerns could be addressed. While there is a cost of living crisis and governments may be more hesitant than ever to use fiscal measures, the consequences of inaction could be even more costly,” Cherry Law, a study author, said in a statement.

The study was published in the journal Nature.