Clean food, detox, paleo – flexitarian, vegan, climatarian? Barely a week goes by without a new hip diet or new way of eating being lauded as the only healthy way forward by various offline and online media.
Most of these trends seem to suffer the same fate as many new products that are regularly launched in food stores. Within a very short time, they disappear from the shelves again and wait to be remarketed as a new discovery at some point in the future. Although nothing has fundamentally changed in this (re)-innovation cycle over the past decades, we can observe some changes in the normative corset of Western food cultures that reflect deeper changes in direction.
After a series of economic crises and the first and second world wars, with all the deprivations they entailed, food culture in Central Europe largely focused on good plain hearty food. This was protein-rich, high in calories and often contained a good measure of alcohol. Back then, the main purpose of nutrition was to satiate hunger, just as common agricultural policy in the early years of the European Community almost exclusively pursued the aim of maximising production. However, the growing introduction and awareness of health and environmental issues that resulted from maximised production led to nutrition becoming an increasingly political and moral concern in the following decades. It was no longer possible to enjoy without a guilty conscience. The dogma of maximisation was succeeded by the optimisation principle. Consumers are becoming more demanding and health-conscious; the origin and nutritional value of food is becoming increasingly important, and sustainability as a (well-worn) collective term now dominates the debate over nutrition of the present and future.
Nutrition, the environment and global boundaries
Independent working groups in the U.S. and Germany came up with the first ideas for a more comprehensive approach to sustainable nutrition in the 1970s and 1980s that gave consideration to health and environmental aspects. Groundbreaking works in this context were “Diet for a Small Planet” by Moore- Lappé (1971), the concept of ‘wholefood’ proposed by Körber et al. (1982) and the ‘Dietary Guidelines for Sustainability’ postulated by Gussow (1986 (5). The first nutrition-related environmental analyses that served in part as the basis for these concepts and addressed specific issues at indicator level even go back to the 1950s and 1960s. Thus, for example, Swedish author Georg Borgström introduced the term of ‘ghost acreage’ (spökareal in Swedish) back in 1953. Today, this is taken to mean “the virtual area footprint”. In the wake of the oil crisis in the early 1970s and following the 1972 study published on behalf of the Club of Rome, Limits of Growth, calculations related to foodstuffs mainly concerned the scarcity of fossil fuels and abiotic resources (minerals used to manufacture fertilisers, etc.). Slesser et al. (1997) additionally investigated the energy intensity of different consumption patterns. As part of the discussion surrounding the anthropogenic influence on the greenhouse effect, which gained momentum following the publication of the report Our Common Future by the United Nations World Commission on Environment and Development (the so-called Brundtland report, 1987), there was a greater focus on analysing and assessing the influence of products, processes and systems in terms of their impacts on the climate.
In connection with a Study Commission on “Preventive Measures to Protect the Earth’s Atmosphere”, the climate relevance of Germany’s food sector was roughly analysed for the first time in 1989. Of the total greenhouse gases emitted in Germany at that time (1.2 billion tonnes of CO2 equivalent), 260 million tonnes were due to the food sector (proportion: 22%). This proportion was calculated to be 25% in 2006 (240 million tonnes out of a total of 960 million tonnes). The relative increase is mainly due to the fact that the agricultural and food sector, unlike other sectors of industry, has contributed less to avoiding greenhouse gas emissions. This underlines the need to take more action in this field in future. Otherwise, it will be hard to reach the climate goals Germany has set itself (reduction of >40% by 2020 as compared with 1990, and of 80-95% by 2050).
Over 30% of global greenhouse gas emissions are caused by the food sector. The lower proportion in Germany is due not to more climate-friendly eating habits, but to the relative strength of the energy and industry sector. Based on the planetary boundaries concept, it was possible to demonstrate that activities in the agricultural and food sector already overstep four of the nine quantified boundaries on a global scale. The nitrogen and phosphorus cycles have the highest relevance due to excessive nutrient inputs, followed by excessive land use and the loss of biodiversity caused by agriculture and food production (see diagram).
Recommendations for sustainable nutrition
Although the subject of sustainable nutrition is often addressed in the context of ecology and environmental protection, this concept also has a health dimension as well as economic and social aspects. Thus, the Food and Agriculture Organization of the United Nations (FAO) defines sustainable diets as follows:
“Sustainable Diets are those diets with low environmental impacts which contribute to food and nutrition security and to healthy life for present and future generations. Sustainable diets are protective and respectful of biodiversity and ecosystems, culturally acceptable, accessible, economically fair and affordable; nutritionally adequate, safe and healthy; while optimizing natural and human resources.”
Many ecological goals can be reconciled with dietary recommendations without any problem. Meat consumption is simultaneously considered one of the main factors for dietary greenhouse gas emissions and a risk factor for various lifestyle diseases. Eating less meat and more plant-based foods would therefore be desirable both for ecological and health reasons.
Conflicts of interests: ecology vs. health recommendations
(Presumed) conflicts of interest arise particularly in the field of tension between health recommendations and ecology. These need to be addressed in more detail. Whereas measures such as reducing meat consumption take both aspects into account, as outlined above, other subjects are being hotly discussed. Fish consumption is foremost among these. While official dietary recommendations advise us to eat more fish because of its favourable fatty acid composition and its content in omega-3 fatty acids, and consumers often eat fish for health reasons, an increase in consumption would increase the already heavy load on the marine environments. Proposals on how to resolve this conflict range from the greater use of alternative sources such as algae or algae oil, the expansion of sustainable fishery and fish farming to questioning the need for these recommendations and the propagated health benefits. Thus, while an analysis by Jenkins et al. pointed to a reduction of 15-20% in deaths from cardiovascular diseases, this reduction was also achieved and even exceeded by an overall sustainable lifestyle. Studies involving vegans who eat no animal-based foods at all, i.e. no fish either, also provide information in this context. The findings are comparable both with regard to cardiovascular diseases and to overall mortality, or even point to advantages over an omnivorous diet (25), provided attention is given to a balanced diet. Garnett puts this more drastically: although the body is highly inefficient at converting the alpha linolenic acid (ALA) found in plant-based food into long-chain eicosapentaenoic acids (EPAs) and docosahexaenoic acids (DHAs), a large number of non-fish eaters in countries far from the coast also lived to be older than average and were healthy without the “ready-to-eat” long-chain omega-3 fatty acids from oily fish.
The same is true of milk and dairy products. While these bear a share of the responsibility for high greenhouse gas emissions via cattle-raising, they are recommended for growing children and elderly people because of their calcium content. Although calcium requirements can also be covered by other foods, as can the needs for other constituents of dairy products, in practice it becomes apparent that vegans, for example, have an inadequate intake and thus a higher risk of bone fractures in old age. This means the situation is basically the same as with fish consumption: the recommendations made by nutrition societies are relevant when they are pragmatically guided by actual eating habits and nutritional knowledge of the population, not by ideal ones.
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