Eating healthily and sustainably

Reducing meat and calories is a win-win for health and the environment. An optimised Low Lands diet is a Dutch concept to make the transition more culturally acceptable.

The fact that there is a positive relationship between sustainable diets and healthy diets has been highlighted by several studies.

In his doctoral thesis “Simultaneous optimisation of the nutritional quality and environmental sustainability of diets”, Corné van Dooren examines this relationship and tries to find constructive ways to benefit from it, killing two birds with one stone, so to say.

He notes that within the Dutch population the action that has the greatest for potential to make our diets healthier and more environmentally friendly is to reduce meat consumption. Second comes eliminating over-consumption of food and eating less calories. Though this is often emphasised from a health perspective, over-eating is less commonly seen as an environmental concern.

In one of the papers he presents an “optimised Low Lands diet”, which was designed with the help of linear modelling and is based on the diet that was commonplace in the Netherlands in 1900–1940, a so-called “traditional Low Lands diet”. The idea is that a food regime that has historical roots in the region is more culturally acceptable than a diet that is not. At least in the case of the Netherlands the diet of the early 20th century was both healthier and more sustainable than the current diet. Tweaking this traditional diet by exchanging as few food items as possible for the greatest environmental and health gains shows where we need to put in the effort for dietary change.

In short, the optimised Low Lands diet would mean a massive increase in vegetables (+85%), fruit (+218%), legumes (+1600%) and potatoes (+227%), combined with a reduction in meat consumption (-58%) and extras (-69%). Cheese is also eliminated from the diet. Fish consumption is also tripled, which may be questionable from a sustainability point of view, but is allowable based on the parameters used: land use and greenhouse gas emissions.

Unlike many similar attempts to design diets, extras such as cake, jam etc., were not totally excluded, but kept at the same level as the traditional diet, 30 g a day. Beer was treated similarly, allowing 300 ml a day, which is actually higher than the current consumption.

The resulting optimised Low Lands diet is also compared to two previous concepts for regional diets: the Mediterranean diet and the New Nordic Diet. Based on the chosen parameters the optimised Low Lands diet was assessed to be as healthy as the Mediterranean diet and a little less healthy than the New Nordic diet, but performed better in reducing greenhouse gas emissions and land use.

The reason why the optimised Low Lands diet performs better can be found in the so-called “vegetable paradox”. The paradox is that increasing the amount of vegetables and fruit in the diet makes it healthier, but not necessary more sustainable. In short, if vegetables and fruit replace meat and cheese in the diet they result in lower greenhouse gas emissions, but when they replace potatoes and grains they most often lead to higher greenhouse gas emissions. Both the Mediterranean and the New Nordic diets have a very high share of vegetables and fruit but are rather low in potatoes and grains compared to the optimised Low Lands diet.

The study also dismisses the notion that eating sustainably and healthily is out of the reach of poor people. A sustainable diet is not necessarily more expensive. With the help of modelling, van Dooren manages to design a healthy weekly shopping basket, with low greenhouse gas emissions and land use, for a two-person household for less than €40 per week. However, it is also noted that food prices in the Netherlands are among the lowest in Europe. And there is also no analysis of other barriers than price that might prevent less-affluent citizens having access to healthy and sustainable food.

Somewhat related to this is an attempt to find patterns of eating habits among different population subgroups. However, the normal divisions by age, gender, income and education prove to be a poor tool for this type of analysis. Although women, older and well-educated people tended to eat healthier, and women, the unemployed and non-European immigrants had diets with lower greenhouse gas emissions compared to the average, there was great variation within those groups.

Another approach was to look at groups classified by their social status (low, middle and high) and values (traditional, modern and postmodern), using a method called social milieus or mentality milieus.

Van Dooren presents an idea for using specific strategies to improve the diet from a sustainability and health perspective. The strategies he suggests are:

1. Replacing snacks with fruit, especially between meals
2. Replacing cheese with vegetables
3. Partly replacing meat with fish
4. Drink less alcoholic beverages
5. Halving the daily portion of meat.  

For example, “New conservatives” – people with high status and traditional values – tend to eat more meat and snacks than average and should be targeted with messages 1) and 3). Looking at crude consumption figures also shows that lifestyles and attitudes that seem to favour sustainability are not always enough. One example is the group “Cosmopolitans” –people with high status and modern values. They tend to have progressive attitudes towards different innovative sustainability concept, such as local foods, artisanal production and urban farming. But they eat more cheese than average, which also leads to higher greenhouse gas emissions than the average Dutch population, and van Dooren suggests that they should be targeted with message 2).

Vegetarianism varied significantly among the groups. It was most common in the group of “Post-materialists”, people with postmodern values and low to medium status, of which 10 per cent were vegetarian compared to 3 per cent in the population as a whole.

The general conclusion from this study is that changing diets can reduce greenhouse gas emissions from food substantially. However, changing people’s eating habits is a complex issue and a combination of practical approaches needs to be tested and investigated.

Kajsa Pira

“Simultaneous optimisation of the nutritional quality and environmental sustainability of diets” by Corné van Dooren, https://research.vu.nl/en/publications/simultaneous-optiimisation-of-nut...