What is the ‘Planetary Health Diet’?

If you’ve been reading up on sustainable food, you may have heard about the so-called ‘Planetary Health Diet.’ In January of 2019, a group of 37 leading researchers on sustainability and nutrition from 16 countries published the EAT-Lancet Commission on Healthy Diets From Sustainable Food Systems. Its objective was to answer one vital question: Can we feed a future population of 10 billion people a healthy diet within planetary boundaries? (EAT-Lancet) 

What Problem Were They Trying to Solve? 

Our current diet and food production system is both unhealthy and unsustainable – what the authors call a lose-lose diet. As they point out, although we produce more than enough calories to feed the global population, more than 690 million people have insufficient food,* while others consume low-quality diets that result in micronutrient deficiencies or contribute to a rise in the incidence of obesity and non-communicable diseases like coronary heart disease, stroke and diabetes. (Food in the Anthropocene, 447). 

At the same time, current food production systems are a major contributing factor to global environmental problems. ‘Food production is the largest cause of global environmental change. Agriculture occupies about 40% of global land, and food production is responsible for up to 30% of global greenhouse-gas emissions and 70% of freshwater use,’ (Food in the Anthropocene, 449). 

Not only is our current system therefore contributing to the degradation of the natural world, but this is a vicious circle that then impacts food production itself, with climate change reducing crop yields around the world (Food in the Anthropocene, 474, panel 5). 

What Recommendations did the EAT-Lancet Commission Make in Their Summary Report?

The report centred on three recommendations: 

1. 1. A global shift toward healthy diets; 
   2. improved food production practices; and 
   3. reduced food loss and waste. (Summary Report, 14)

For the first point, the recommendation was what the authors call the ‘universal healthy reference diet,’ which aims to address both nutritional and environmental considerations: 

‘Our universal healthy reference diet largely consists of vegetables, fruits, whole grains, legumes, nuts, and unsaturated oils, includes a low to moderate amount of seafood and poultry, and includes no or a low quantity of red meat, processed meat, added sugar, refined grains, and starchy vegetables,’ (Food in the Anthropocene, 485). 

At the same time, the authors also pushed for the adoption of major shifts in food production. Their seven key recommendations include decarbonising food production, feeding humanity on existing agricultural land instead of clearing more forest to make way for farms, and urgently stopping biodiversity loss – that is, the loss of the variety of plant and animal species (Food in the Anthropocene, 469).

The final, vital component of the report’s recommendations is a drastic reduction in food waste. Food waste happens all along the production chain, from the initial food production stages on the farm – for example, through poor harvest scheduling and timing, poor storage facilities or contamination – through to transportation and retail. However, the report also points out that ‘particularly in highly developed countries, the public is responsible for a large proportion of food waste. The Commission envisages the use of campaigns to promote improved planning of purchases, understanding of best before and use by labels, storage practices, assessment of portions needed, food preparation techniques, and knowledge of how to use leftovers,’ (Food in the Anthropocene, 482). 

Limitations & Misconceptions

The EAT-Lancet report sent shockwaves through both academia and social media, which has generated some confusion about what it really advocates and how it can or should be applied. 

1. The planetary health diet is not a vegan diet. The authors do note that 

‘Vegan and vegetarian diets were associated with the greatest reductions in greenhouse-gas emissions and land use and vegetarian diets with the greatest reductions in water use … studies show a diet including more plant-based foods than animal-source foods would confer environmental benefits and improved health.’ (Food in the Anthropocene, 470). 

However, the reference diet does allow for some meat, poultry, seafood and dairy consumption. In certain contexts, for example in regions where people have inadequate nutrition, the authors also recommend a more nuanced look at the optimal amount of various sources of protein that should be included in the diet, and acknowledge the importance of animal-source foods in addressing undernutrition. So while the report does advocate ‘substantial shifts toward mostly plant-based dietary patterns’ (Summary Report, 16), it does not advocate a blanket ban on meat or foods from animal sources. 

2. The report is also not meant to be a dietary guideline for individuals. Of course, the hope is that the diet will be used as a basis for the compilation of national and industry guidelines. However, it is not an actionable dietary guideline itself. Its recommendations still need to be adapted to local socio-economic conditions, traditions, available foods. 

One example of how this might be achieved is in Lassen, Christensen and Trolle, ‘Development of a Danish Adapted Healthy Plant-Based Diet Based on the EAT-Lancet Reference Diet.’ This models a potential dietary guideline for Danish consumers based on the reference diet. It is one example of how the diet might be adjusted to suit local tastes and conditions. 

Adaptation to local conditions is particularly important in areas where the foods that are foregrounded in the Planetary Health Diet may be unaffordable and, as noted above, in contexts where undernourishment is a concern. 

3. There is no scientific consensus yet. The Planetary Health Diet may sometimes be discussed as though it were an official nutrition guideline, but it is important to note that there is no scientific consensus as yet on this proposal. This report was a massive undertaking and offers an exciting direction for research and policy, but its conclusions and implications are still being debated within the scientific community. For an example of discussions on one point of the study, see here (PDF),  and here (PDF).

* Food in the Anthropocene sets this figure at 820 million, citing the 2018 Food and Agriculture Organization of the UN, International Fund for Agricultural Development, UNICEF, World Food Programme, and WHO report ‘The state of food security and nutrition in the world’. However, the 2020 version of this report recalculates this value to 690 million as better data has become available. 

Photos by Courtney Smith and Kelly Neil on Unsplash