Study by the University of Bonn investigates tradeoffs between human health and sustainability

In sub-Saharan Africa, many people are undernourished or malnourished. A new study by the Universities of Bonn and Ghana shows how rising incomes and urbanization are influencing dietary patterns of local populations. According to this, the wealthier segments in African countries are increasingly eating like people in Western industrialized countries. Although this improves their supply of important nutrients, it also has a greater negative impact on the environment. The study also looks at how this environmental damage can be minimized. It has been published in the journal ‘Sustainable Production and Consumption.’

One-third of the greenhouse gases emitted worldwide are attributable to food production and consumption. What we eat and drink therefore makes a significant contribution to global warming. Especially in Western industrialized countries, the typical dietary patterns are putting the climate and the environment at risk. “However, the environmental impacts are much lower in countries south of the Sahara,” emphasizes Prof. Dr. Matin Qaim from the Center for Development Research (ZEF) at the University of Bonn.

This is mainly due to two points, as the current study shows: Firstly, many people in Africa simply eat less because they cannot afford it. Secondly, animal-sourced foods such as meat, eggs, and milk are included in their diet relatively rarely. The production of these products is particularly harmful to the environment. At the same time, however, animal products are a rich source of protein and other nutrients. If they are consumed in greater quantities, this can therefore have a positive influence on nutritional status.

Nutritional data from 18,000 households evaluated

The researchers based their analysis on nutritional data from nearly 18,000 households in Ghana, Ethiopia, and Nigeria. This also included information on household income and on whether they lived in an urban or rural area. “We carried out what is known as a life cycle assessment for each food item consumed,” explains Qaim’s colleague Dr. Juliana Minetto Gellert Paris, the lead author of the study.

In doing so, efforts were made to determine as precisely as possible what impact the production of a food item has on the environment: How much land is required for cultivation? How much fertilizer is used? What proportion of it spoils because it does not reach the market quickly enough? How long are the transport routes, and how much fuel is required for this? “Using all of these factors, it is possible to calculate, for example, what quantity of greenhouse gases is generated during the production of one liter of milk or one kilo of maize or cassava flour,” says Gellert Paris.

High-income earners consume similar foods to those in the West

Until now, analyses of this kind have existed almost exclusively for industrialized countries. However, cereals produced in Ghana have different impacts on the environment than cereals from Germany. The production conditions differ significantly, so the same environmental effects cannot be assumed. Nevertheless, reliable figures have largely been lacking for sub-Saharan Africa until now. The current study changes this. It thus offers an in-depth insight into the environmental footprint of the dietary patterns in this region for the first time.

For many people in sub-Saharan Africa, meat, eggs, and milk are a luxury that they can rarely afford. This does not apply to high-income earners, however, as shown by the data: On average, their diets are similar to those of people in Western industrialized countries – with significantly more animal products, but also much more highly processed foods. Their consumption of soda, fruit juices, coffee, and tea was also considerably higher than that of poorer respondents. “A similar trend can be observed among those who live in urban areas,” says Qaim, who is also a member of the Transdisciplinary Research Area (TRA) ‘Sustainable Futures’ and the Cluster of Excellence ‘PhenoRob.’ “This even applies to those who do not earn quite as much.”

Calling for people to give up meat would be both arrogant and cynical

Rising incomes and urbanization are thus causing a change in dietary patterns in sub-Saharan Africa. “Up to a certain level, this is positive,” explains Gellert Paris: “The increased consumption of animal products, in particular, leads to a better supply of important nutrients.” However, this only applies up to a certain point: Too much meat harms not only the environment but also human health.

Around 1.3 billion people currently live in countries south of the Sahara. There are likely to be twice as many in 2050. “Supplying them all with high-quality foods is an urgent goal,” highlights the researcher. “Even if this should require the increased production of animal-sourced products. Given still high levels of undernutrition, it would be both arrogant and cynical to expect the people there to become vegetarians for the benefit of the environment.”

More negative environmental impacts

Overall, it is to be expected that the negative environmental impacts of food systems in sub-Saharan Africa will increase. Nevertheless, the researchers believe that these impacts can be limited – such as by increasing crop yields in agriculture. The less land is needed to produce a certain amount of food, the lower the environmental damage. It is also important to minimize losses. At present, some of the produce spoils before it ends up on a plate – for instance, due to a lack of ways to refrigerate the goods.

“Thanks to technological advancements, the environmental consequences can at least be reduced,” says Qaim. “Alongside this, however, policymakers should attempt to prevent our current Western lifestyle from spreading to African countries through education campaigns. After all, we are certainly not a good role model when it comes to sustainability.”

Participating institutions and funding:

The Universities of Bonn and Ghana were involved in the study. The analyses were supported financially by the Foundation fiat panis and by the TRA ‘Sustainable Futures’ at the University of Bonn.