Nachhaltige Ernährung mit wirklichen Gesundheitseffekten: die 1/7-Regel

von Alexander Schrode

Offizielle Ernährungsempfehlungen preisen eine pflanzenbasierte Ernährung. Aber sie geben keine Angaben, wieviel pflanzliche Produkte mindestens bzw. wie wenig tierische Produkte maximal insgesamt damit wirklich gemeint sind. Können wir diese für Sie ermitteln?

Offizielle Empfehlungen bei tierischen Produkten unklar

Großer Aufruhr brach vor kurzem aus, als die WHO rotes Fleisch im Allgemeinen und verarbeitete Fleischwaren im Speziellen als wahrscheinlich krebserregend einstufte. Dabei empfiehlt selbst die DGE bereits seit einiger Zeit, diese Produkte nur in geringem Maße zu verzehren und vielmehr überwiegend pflanzliche Lebensmittel zu wählen. Hinweise, wie viele pflanzliche Produkte mindestens bzw. wie wenig tierische Produkte maximal wir insgesamt essen sollten, fehlen in den meisten Ernährungsempfehlungen, wie unter anderem die DGE und die USDA, jedoch. Die „10 Regeln“ der DGE beispielsweise enthalten zwar Maximalmengen für Fleisch, aber nicht für Milch und Milchprodukte oder tierische Produkte insgesamt. Können wir dennoch ermitteln, wie groß die Basis sein sollte, d.h. der Anteil der pflanzlichen Produkte an der Ernährung sein, um gesund zu leben?

Gesundheitliche Vorteile von pflanzenbasierter Ernährung

In immer mehr Studien und Metastudien aus umfangreichen Untersuchungen, wie der „Oxford Vegetarian Study“ oder der „Adventist Health Study 2“, zeigt sich, dass eine pflanzenbasierte Ernährungsweise mit weniger tierischen Produkten – wie es in der vegetarischen und veganen Ernährung praktiziert wird – deutliche Gesundheitsvorteile mit sich bringen kann. Dabei sind insb. eine geringere Gesamt-Sterblichkeit123 sowie weniger Krebs-123 und Herz-Kreislauf-Erkrankungen12 hervorzuheben.

Gesundheitliche Nachteile tierischer Produkte

Dies wird unter anderem darauf zurückgeführt, dass in tierischen Produkten zwangsläufig insbesondere gesättigte Fettsäuren, Trans-Fettsäuren und Cholesterin enthalten sind. Gleichzeitig erhöht der Konsum von Fleisch und auch Milchprodukten die Wahrscheinlichkeit, unter anderem Krebs-12345 und Herz-Kreislauf-Erkrankungen1234 zu erleiden. Daher empfiehlt die Harvard Medical School, nicht nur Fleisch, sondern auch Milchprodukte stark auf eine Portion täglich zu reduzieren (zur Vermeidung gesättigter Fettsäuren und der Risikoerhöhung von bspw. Eierstock- oder Prostatakrebs).

Pflanzenbasierte Ernährung: versteckte Hinweise in Leitlinien

Wie wenig tierische Produkte wir insgesamt essen sollten, lässt sich aber zumindest in Bezug auf einige zentrale Aspekte indirekt ableiten, zum Beispiel aus den Empfehlungen zur Zufuhr von gesättigten Fettsäuren und Cholesterin. Pro Tag werden maximal 15 bis 20 Gramm gesättigte Fettsäuren und 275 bis 300 Milligramm Cholesterin empfohlen. Bei diesen Maximalmengen geht es sich wohlgemerkt nicht darum, um eine optimale Gesundheit zu erreichen, sondern darum, nicht das Risiko insbesondere für Herz-Kreislauf-Erkrankungen und Krebserkrankungen überdurchschnittlich zu erhöhen.

Pflanzliche und tierische Produkte: Wie viel ist maximal gesundheitserhaltend?

Was kann man nun essen, um diese Grenzen nicht zu überschreiten? Die folgende Tabelle (nach Bundeslebensmittelschlüssel) zu tierischen Produkten gibt dazu Aufschluss:

tabelle

Nehmen wir folgendes an: Ich verzehre pro Tag nur

  • 150 Gramm Schweinefleisch und ca. 1,5 Eier (und keinerlei Milch, Butter, Sahne, Käse, Quark, Joghurt) oder
  • 40 Gramm Geflügel, 25 Gramm rotes Fleisch, ein halbes Ei, ca. 5 Gramm Butter, 20 Gramm Käse und 6 Gramm Sahne

Dann würde ich folglich bereits ca. 13 Gramm gesättigte Fettsäuren und ca. 230 Milligramm Cholesterin erreichen, ohne auch nur irgendwelche andere Lebensmittel (Chips, Gebäck etc.) gegessen zu haben. Mehr als diese Menge, umgerechnet insgesamt ca. 360 kcal tierische Produkte pro Tag, sollte ich also tunlichst nicht regelmäßig verspeisen, um nicht die Wahrscheinlichkeit für die oben genannten Krankheiten stark zu erhöhen.

Maximale Menge tierischer Produkte: die neue 1/7-Regel

Gehen wir von dem Mittelwert der empfohlenen Energiezufuhr von 2400 Kilokalorien pro Tag aus, könnte als neue Regel bzw. neuer Richtwert abgeleitet werden, dass nur maximal ein Siebtel aus tierischen Produkten und mindestens sechs Siebtel aus pflanzlichen Produkten stammen sollten, um die Gesundheit (in Bezug auf die oben genannten Aspekte) zu erhalten. Momentan besteht die durchschnittliche Ernährung noch zu etwa einem Drittel aus tierischen Produkten. Für die optimale Gesundheit sei noch angemerkt: Es gibt nach vielen Studien Tendenzen, dass eine rein pflanzliche Ernährung aus gesundheitlicher (und ökologischer) Perspektive die größten Vorteile bewirken könnte.

Healthier diets for healthier people: public policies for tackling obesity

by Silvia Monetti

The ongoing epidemic

In this article, we saw that obesity and overweight have become global threats to public health: they are no longer a problem exclusive to high-income countries, but are present worldwide. Obesity is even becoming one of the most frequently diagnosed chronic diseases in many countries, affecting all age groups and especially children. So far, no country has been able to stop the epidemic; obesity and overweight rates are expected to rise, which increasingly affects future societies’ public health (individuals’ quality of life and life expectancy) and economies (higher health-care expenditures in the short- and long-term).

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Prevention is crucial, as food preferences can be learned and unlearned. Policies to promote a healthy nutrition should act on many different dimensions: not only on the biological mechanisms regulating food preferences, but also on the built environment, social and cultural norms influencing learning patterns, marketing, education, working times and free time activities (sport, time spent watching television and playing videogames), transportation, eating habits and the overall food system.

Four mechanisms for effective food policies

The task is challenging: lots of data are required to design effective measures and numerous players and sectors need to coordinate themselves, including national and local governments, private companies, and civil society actors. An interesting article in The Lancet identifies four mechanisms through which food policies may effectively influence eating habits:

  • by providing enabling environments for learning healthy preferences;
  • by overcoming barriers hindering the expression of healthy preferences – healthy foods, for example, tend to be more expensive than less healthy alternatives;
  • by encouraging people to reconsider their unhealthy preferences – for instance by changing price, availability and presentation of healthier foods to encourage consumers to choose them;
  • by stimulating positive responses at the food system level: taxing a certain (unhealthy) ingredient can lead to a reformulation of the products containing it.

Let’s see some examples of these mechanisms at work.

School settings

5819982320_e62574d1a9_bSchools are particularly significant environments for children and adolescences. Nutrition education is important, but knowledge alone might not be sufficient for lasting change. Food policies to promote healthy diets include the provision of fruits and vegetables as free snacks or in school lunches, school gardening, the introduction of vegetarian meals or vegetarian days, changes in the presentation of food. Policies for prevention should involve also children’s families and promote physical activity. Multicomponent interventions are the most effective ones.

Economic instruments

By affecting individuals’ preferences, economic measures such as food taxes and subsidies can potentially reduce (or improve) the consumption of targeted foods and drinks. In the short-term, and in combination with measures to raise awareness, they can lead consumers to reassess their preferences at the point-of-purchase. Over time, by reducing (or increasing) the exposure to certain foods, they can determine long-lasting changes in eating habits and food preferences. If taxes target foods that can be reformulated, their potential of instilling food-systems feedbacks increase. A tax on soft drinks in Mexico, introduced in 2014, has already induced a 12% decrease in the selling of the targeted goods. It is extremely important that taxes and subsidies are well designed. For example, healthier and cheaper foods that can substitute the taxed ones need to be available – otherwise, consumers will just buy more of other non-targeted, less healthy foods.

Labelling

Nutrient lists can be difficult to comprehend; such labels are useful especially for people already willing to consume healthy foods and looking for this information. Labels displaying foods’ calories or nutrient content with different colours or simple words are easier to understand but, still, their effectiveness depends much on consumers’ preferences and intentions, purchasing occasion, food type etc. Nonetheless, labelling of calories or other nutrients can determine responses at the food system’s level: for example, mandatory trans fat labelling in South Korea and the USA have led to the reformulation of certain food products, with an improvement of their nutritional quality. Nutrition labelling can thus serve as an incentive for food producers and retailers to change their offer.

Adopting a comprehensive approach

6621230205_83c6cc8db1_bIntegrated policies to prevent obesity and promote healthy diets and lifestyles are urgently needed at the local, national and global level. Measures include restrictions in the marketing of food aimed at children, regulation of food nutritional quality and availability in schools, nutrition labelling, food taxes and subsidies, public-private partnerships, information and awareness campaigns, the adoption of comprehensive health-in-all-policies approaches. Involving all food system’s actors is crucial. Recently, Mars food advised to consume some of its products only occasionally, due to a high salt, sugar or fat content.

What do you think?

 

 

Obesity in low- and middle-income countries: the unexpected side of a global epidemic

by Silvia Monetti

futurediets1A story of paradoxes

In a world where 870 million people still don’t have access to sufficient and nutritious food, over 1.3 billion people are overweight and 600 million obese. More than half of the world adult population experiences this condition. Obesity and overweight, the other face of malnutrition, have been rising particularly fast in low- and middle-income countries –so rapidly that the World Health Organization has started talking of a “global epidemic”.

Shares are higher in some parts of Latin America, the Middle East, North Africa and the Pacific, and lower in other regions of Africa and in Asia. In North Africa and the Middle East over two-thirds of the women are overweight or obese, while about half of them are affected in Latin America and the Caribbean.

Changing dynamics

According to the report “Future diets” of the Overseas Development Institute,

“what has changed is that the majority of people who are overweight or obese today can be found in the developing, rather than the developed, world”.

As a result, such countries face a “double burden” of disease: on the one hand, infectious diseases, undernutrition and the related problems – such as damages to the mental and physical development of inffuturediets-2ants and children, harming their life perspectives; on the other hand, increasing obesity and overweight, equally serious threats to public health: they increase the likelihood of diabetes, hypertension, coronary heart disease, premature death, stroke, some types of cancer and other serious chronic conditions. Severely obese people die 8-10 years sooner than those of normal weight, and this condition is globally linked to more deaths than underweight. All of this is very costly for the whole society, weighing onto health expenditures and economies in the medium- and long-term.

Deep roots

The primary cause of obesity and overweight is an energy imbalance between the calories consumed and those expended – people simply eat more food than they need. In developing countries, increasing income and urbanization are leading to a higher food intake, particularly of animal origin and processed foods that are richer in salt, fat, sugar and caloric sweeteners than the traditional ones. At the same time, increasingly sedentary occupations, transformations in the modes of transportation and the proliferation of urban settings diminish the level of physical activity. Such dietary changes are not necessarily negative. An increase in consumption of animal origin food, for example, can considerably improve the nutritional profile of poor individuals’ diets – but an excessive consumption determines a too high intake of saturated fat and is linked to many different serious diseases. Healthy diets include a high proportion of fruits and vegetables. However, as a country’s economic development improves, grains, vegetables, starchy staples and fresh fruits become increasingly expensive. Junk foods, at the same time, become relatively cheaper. An example: between 1990 and 2012 the price of fruit and vegetables has increased by up to 91% in Brazil, China, Korea and Mexico. Conversely, that of ready meals has dropped by up to 20%.

icecreamGlobalization and changes in the food system, like the diffusion of new technologies for food production, transportation, distribution and marketing, are other key drivers of the epidemic. Fresh markets are being replaced by supermarkets and megastores – promoting safety standards but also enhancing the access to cheaper processed foods high in fat, added sugar and salt. The liberalisation of trade and investments has allowed international companies to set up processed food factories or open fast-food franchises worldwide. In Brazil, the consumption of “ultra-processed” ready-to-eat drinks and foods has risen from 80 kg per person per year in 1999 to around 110 kg per person per year by 2013. In South Africa, the cost of a “healthy diet” is 69% higher than that of a typical one.

Fighting the epidemics

Effective policies have to act on multiple fronts, addressing at the same time individual choices, through information, education and economic instruments, and the food industry, through better regulations of food production and marketing. Sure, this is easier said than done: nutrition is a field particularly difficult to tackle. Governments and international agencies have to deal simultaneously with powerful lobbies and a sensitive, primarily private sphere. Still, in 2014, Mexico – a country where 33% of children and adolescents and over 70% of adults are overweight or obese – introduced a 10% tax on sugar-sweetened beverages. Their consumption had grown parallel to obesity rates. In just one year, taxed soft drinks’ purchases diminished by 12%. Find out more about effective policies for preventing obesity here !