Our health and what we eat are inextricably linked. A balanced, nutritious diet gives us energy, keeps us focused and keeps many medical conditions at bay.

But what and how we eat is just as important to planetary health, and right now our diets are helping to create a sickly Earth. Growing consumption of resource intensive-food, such as (red) meats, ultra-processed food, combined with a huge amount of food waste, is driving the conversion of land for agriculture—which is destroying ecosystems, reducing biodiversity, and contributing to climate change.

One third of our food is lost or wasted, generating eight per cent of greenhouse gas emissions at a cost of US$1 trillion per year. This is happening while 820 million people are undernourished. Emissions from the food sector could rise 40 per cent by 2050.

Momentum is growing, however, for a shift to sustainable diets that protect the health of people and planet. At the C40 cities network summit in Copenhagen, just before this year’s celebration of World Food Day, 14 cities signed up to the Planetary Health Diet. If adopted universally, this diet would reduce greenhouse gas emissions, feed 10 billion people and save 11 million lives each year.

According to the EAT-Lancet Commission, a planetary health plate should consist largely of vegetables and fruits, with the rest made up with whole grains, plant protein sources, unsaturated plant oils, and, occasionally, small amounts of meat or fish.

Mayors from Barcelona to Toronto are promising to change the food cities buy, cut food loss and waste, and introduce policies that make healthy and low-carbon food affordable and accessible.

“The old saying goes, ‘You are what you eat’, but our planet is also being shaped by what we put in our stomachs,” said Clementine O’Connor, Programme Officer on Sustainable Food Systems. “We all need to think more carefully about diets that improve planetary health, as well as our own.”

The UN Environment Programme (UNEP)—which works with C40 on a range of issues—is doing its part to reform food systems and bring a host of environmental benefits. UNEP works with the One Planet Network Sustainable Food Systems Programme in three key areas.

Governance

It supports countries to implement better governance and sustainable food systems policies and indicators that link environmental conservation, health and nutrition and food security. UNEP in June launched a policy guideline, the Collaborative Framework for Food Systems Transformation, to provide practical recommendations.

Food waste

As custodian of the food waste indicator for Sustainable Development Goal target 12.3 on food loss and waste, UNEP is developing a food waste index to track country progress, and is improving the ability of countries to measure food waste and develop national strategies. UNEP’s longstanding public campaign on food waste, Think Eat Save, published guidance for food waste prevention programmes for countries and companies. With the World Resources Institute, UNEP is developing an initiative with 10 of the world’s largest retailers to halve food waste in their supply chains by 2030. Through the One Planet Network’s Sustainable Tourism Programme, UNEP co-develops national roadmaps for the tourism sector and hotels to address food waste and single-use plastics together.

Sustainable diets

Together with the Food and Agriculture Organization of the United Nations, UNEP will build capacity and increase awareness on healthy and sustainable diets through the UN Decade of Action on Nutrition, through regional workshops that identify trends and drivers for a shift towards sustainable diets, gathering and sharing knowledge and experiences in developed and developing countries.