How to eat to save the world

LONDON — There is not a country in the world that is not grappling with the serious health and environmental consequences of their people’s diets. There has to be a better way to feed everyone well and sustainably.

As it stands, roughly 820 million people worldwide lack sufficient food, and many more — often in the same countries — consume unhealthy foods that lead to obesity, heart disease, diabetes and other life-limiting conditions. The health risks of poor diets now outweigh the combined impact of alcohol, smoking, unsafe sex and drug abuse.

On the environmental front, global food production is the single largest source of human pressure on the planet’s resources, using 40 percent of the world’s land and 70 percent of its freshwater. It also contributes substantially to rising greenhouse gas emissions, loss of biodiversity, the emergence of ocean dead zones and deforestation.

With the global population set to reach 10 billion by 2050, the challenge of feeding the world in a healthy and sustainable way will only deepen. Meeting that challenge will require major, long-term systemic changes. A good place to start is the set

of science-based guidelines recently released by the EAT-Lancet Commission on Healthy Diets from Sustainable Food Systems, funded by Wellcome (with which both of us are affiliated).

In the proposed “win-win” diet, approximately one-third of calories would be acquired from whole grains and tubers; protein would come primarily from plant sources, though about a half-ounce of red meat per day would also be included; and about 17 ounces of fruits and vegetables would be consumed daily. On average, the diet would halve global consumption of red meat and sugar, and more than double the amount of fruits, vegetables, nuts and legumes consumed worldwide today.

Of course, given the diversity of food systems around the world, not to mention the role of culture and tradition in shaping diets, specific components would need to be adapted to local needs and tastes. But, if the entire world adopted a version of this diet, up to 11.6 million premature food-related deaths could be prevented every year.

The commission’s report sets out clear strategies for making that happen, with international organizations and national governments taking the lead in ensuring that healthy, sustainable diets are available, attractive and affordable for all. Implementing them will require, first and foremost, an overhaul of countries’ agricultural sectors, to ensure they are providing the diet’s necessary components. Rather than basing decisions solely on production levels, farmers need to produce sufficiently diverse products and adopt sustainable practices. To that end, effective incentives will need to be created.

Moreover, in low-income countries, strengthening the infrastructure linking rural farming communities with urban centers would go a long way toward expanding access to fresh, healthy produce, while reducing waste associated with transportation. In fact, if one accounts for the entire supply chain, almost one-third of all food produced worldwide is being wasted. Given this, national waste-reduction programs will have to complement higher investment in infrastructure.

Likewise, in order to ensure long-term global food security, more resources must be directed toward the development of more nutritious, higher-yielding and more resilient crops that can withstand temperature fluctuations, extreme weather and pests. Whatever new seeds are developed must be made available and affordable for farmers worldwide. In the meantime, farmers in arid regions need better access to existing drought-tolerant crops, such as the high-protein legume cowpea, in order to protect soil and preserve moisture.

More generally, a sustainable diet requires the world to improve its stewardship of the planet. This means taking action not just to slow deforestation, but also to reforest degraded land, as well as to protect marine biodiversity and prevent the expansion of agricultural land.

The EAT-Lancet Commission’s report does not have all the answers. More work is needed, for example, to determine how best to transform food production in low-resource settings. But the evidence-based strategy the report advocates provides a useful framework for all stakeholders—including governments, producers and citizens—to cooperate in transforming unsustainable food systems and ensuring a healthy diet for all. Project Syndicate

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Modi Mwatsama is senior science lead in food systems, nutrition, and health at Wellcome’s Our Planet, Our Health. Howard Frumkin is head of Wellcome’s Our Planet, Our Health.