Healthy and sustainable diets for people and planet
The EAT-Lancet study and our insights into healthy and sustainable food
On 16 January this year the medical journal The Lancet published the report ‘Food in the Anthropocene: the EAT-Lancet Commission on healthy diets from sustainable food systems’. The report is the result of a scientific quest for a healthy and sustainable diet. The report is the outcome of a three-year collaborative effort by 37 scientists with a range of expertise to reach consensus on a healthy and sustainable food system for the world. The central question they set out to answer was ‘How can we feed about 10 billion people in 2050 with healthy and sustainable diets?’
The study reveals that radical changes are urgently needed. Our dietary patterns must be altered and the food production system must be transformed. Despite the urgency and necessity of change, the Commission’s message is positive. It can be done: implementing the proposed changes will keep people and planet healthy. The report’s message has received a mixed response. The media focused on the need to radically change our diets. In addition, some commentators argue that the proposed dietary pattern is totally unfeasible, that people are unwilling to change, and certainly not when they are told they have to. Others have doubts about the nutritional balance of the proposed dietary pattern.
However, the fact remains that at the moment there is a tremendous imbalance in the world. A large proportion of the world's population consume unhealthy diets. Too many people suffer from obesity, diabetes and cardiovascular diseases, while others have insufficient food and a drastic shortage of nutrients. In addition, the food system has a huge impact on the environment, is a major contributor to global greenhouse gas emissions and makes a big claim on scarce natural resources.
In short, the current situation is unhealthy and unsustainable. We too believe this must, and can, change.
Insights into healthy and sustainable diets
Over the years Blonk Consultants has carried out studies and obtained insights into healthy and sustainable diets. In 2015, for the Dutch environmental organisation Natuur & Milieu we investigated what a healthy and sustainable diet pattern would be for the Netherlands. The result is the Menu for Tomorrow (Menu voor Morgen). In 2017, for WWF UK we performed a similar study that resulted in an update of the Livewell Plates (diets that are good for people and the environment). We investigated what the residents of the UK should be eating in 2030 and 2050 to reduce UK greenhouse gas emissions by 60% and keep the global temperature rise within the two degree limit.
Same conclusions, different assumptionsWe arrive at roughly the same conclusion as the EAT-Lancet Commission: a more plant-based dietary pattern consisting of vegetables, pulses, nuts and whole grains alongside dairy products and fish, but less animal protein and added sugars.
Our research method was different, and actually more precise, with fewer limitations than the Lancet study
Predetermined dietary patterns vs optimisation
One of the differences is that the EAT-Lancet Commission starts from a number of predetermined dietary patterns, such as semi-vegetarian (‘flexitarian’), pescatarian, vegetarian and vegan. This means that the amounts of the different types of foods are fixed in advance. In our studies we chose an ‘optimisation’ approach in which we look for an optimum dietary pattern derived from nutrient needs and sustainability targets. This method ensures that an optimised dietary pattern always meets nutritional requirements, such as the right number of calories and a sufficient intake of vitamins and minerals. It leads to different results because there are more degrees of freedom, and it even generates a dietary pattern with a lower environmental impact than an approach based on a predetermined reference dietary pattern. .
Whole life cycle of food products taken into account
Another important difference is that we critically examined the whole life cycle of the food products, whereas the Lancet study focused on agricultural production. This means that the Lancet study underestimates the environmental impact of some foods, because for some foods the bulk of impacts are not caused during primary production, but elsewhere in the life cycle, such as the manufacture of the packaging or the preparation of the meal by the consumer.
Moreover, unlike the EAT-Lancet Commission, we did not use production and export figures to describe current dietary patterns. Our calculations are based on the Dutch National Food Consumption Survey, so the amounts reflect real consumption by consumers. The difference in the outcome is well illustrated by the product group ‘oils’. The Lancet study assumes that all the vegetable oils available in a country are consumed, but that is not a sound assumption (frying oils being a case in point).
Feasibility of new dietary patterns
Finally, a further aspect in our approach is that new dietary patterns diverge as little as possible from the current (average) dietary pattern in a country, making them more accessible to consumers. A healthier and more sustainable diet can be achieved simply by making relatively small adjustments.
Optimeal: calculate healthy and sustainable diets
A key element in our study was Optimeal, a tool for optimising dietary patterns for both health and sustainability. The program adjusts the food components of diets until an optimum dietary pattern is reached that meets all the conditions required of it (health and sustainability). It is also possible to optimise diets for other indicators, such as price. Optimeal contains reliable data on the nutritional properties of foods and on their environmental impacts, such as carbon footprint, land use and depletion of fossil fuels.
Follow-up actionsNow that the world has been given a clear message (and faces a considerable challenge), action must be taken. What the next steps will entail and who will take it upon themselves to act remains uncertain. First of all, the reference dietary pattern needs to be translated into concrete diets. These should be country specific, because each country has its own eating habits, dietary needs and available foods. A major issue is feasibility: are consumers prepared to adapt their dietary patterns and intake, and how big a change is needed? Here lies a task for government and industry. But how much can governments ‘determine’ what their populations may and may not eat? And how can this be laid down in policy? Will food companies really make their products healthier and more sustainable? Will the environmental impact of the agricultural sector be reduced? Swift action is clearly needed. Already thousands of guidelines and recommendations have been developed for making the food consumption system healthier and more sustainable. Let us hope that all parties take up the challenge and act to keep people and planet healthy.
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