What is a sustainable and healthy diet? We ask a world-renowned scientist and sustainability expert

By Allyson Shiffman

Not only is food responsible for one-third of our current climate crisis, it’s also the single largest killer on planet earth. Dr Johan Rockström, a scientist and sustainability expert, gives us a surprisingly straightforward roadmap on how to eat sustainably

Food – what we consume and how we produce it – is responsible for one-third of our current climate crisis. What’s more, malnutrition is the single largest killer on planet earth. Unhealthy food and responsible for a staggering 11 million premature deaths each year. According to Dr Johan Rockström, a Swedish scientist who is among the most important minds and voices when it comes to solving our current climate crisis, the food system is “the single greatest threat to our future on planet earth”.


Rockström led the development of the nine planetary boundaries, a scientific framework that lays out nine areas (among them, climate change, global freshwater use, chemical pollution) and the limits we must adhere to in order to sustain a liveable life on our planet. So far, we have crossed six of those boundaries.

Now for the good news. According to Rockström, by implementing a more sustainable food system, we can transition back within the boundaries of four areas: freshwater biodiversity, nitrogen overloading, phosphorus overloading, and greenhouse gases. What’s more, the resulting “sustainable diet” would save those 11 million premature deaths due to an unhealthy diet.

But how exactly do we achieve this? Rockström and a team of 36 scientists have laid out a roadmap in The EAT-Lancet report, an academic paper that lays out what constitutes a healthy diet derived from a sustainable food system. As individuals, eating sustainably is a first, very actionable step to take towards ensuring a healthy future for our planet. Below, Rockström and EAT-Lancet’s simple guide for a sustainable diet.

More vegetables, more fruit, more nuts

“Nuts are proven to be the most healthy, protein-rich food item,” says Rockström. In fact, you should aim to consume at least 125 grams of dry beans, lentils, peas and other nuts or legumes per day.

Less animal protein

Meat eaters will be happy to learn that meat is not out completely, however, in the Western world, including the Nordics, we would have to cut back on our consumption of red meat by a factor of three or four. According to Rockström, that means one serving of meat (3 to 4 ounces) per week, two servings of fish and two servings per week of white meat.

Less starchy kilo-calories

Instead, go for full-grain cereals.

Reduce waste

Pack up excess food into a lunch box or repurpose it into a new recipe. Less waste means less food production, which is good for the planet as well as your wallet.

Rockström summarises the ideal sustainable diet simply: “So it’s less animal protein, much more nuts, vegetables, fruit and much less starchy kilocalories and energy sources. Plus full grain cereals,” he says. “And that’s basically the package.”