Researching the best and sustainable diet

Researching the best diet

How studies help to learn more about healthy and sustainable diets

The topic of nutrition accompanies our lives. Some people think of our grandma's delicious fried potatoes, others of the cheap pizzeria next door and others of a new favorite dish from their last vacation in Turkey. Nutrition is always individual and includes topics such as one's own culture, current phases of life or personal preferences.

But of course, nutrition has a major influence on how healthy we are - and how healthy we stay. The risk of disease can be increased or effectively reduced. In addition, our diet is important for the health of our planet. And often the two go well together. The findings from studies help us on the way to a healthy and sustainable diet.

Which nutritional studies can you trust?

The number of studies published each year is huge. It is not easy for those interested to filter out the best results. When it comes to nutrition, a look at the World Health Organization (WHO) and the recommendations of national professional societies is helpful, as they are based on the latest studies.

The WHO recommendations on nutrition

The World Health Organization published the latest guidelines for a healthy diet in 2023.

Basically, the WHO states that in Europe, eating habits and food systems in general are neither healthy nor sustainable. Unhealthy eating habits are one of the leading risk factors for diseases - from cardiovascular disease and diabetes to cancer - and are responsible for a fifth of all deaths worldwide. Over 2 billion people worldwide are overweight, and in Europe it affects a third of all primary school children. A balanced and varied diet consisting of a wide range of foods, on the other hand, extends life by years.

The WHO therefore promotes a diet that reduces deficiencies and risks. What should you bear in mind? The calorie intake should correspond to your own needs. Fat should not make up more than 30% of the diet - with a maximum of 10% saturated fatty acids (primarily animal fats) and less than 1% trans fatty acids. Trans fatty acids are a subgroup of unsaturated fatty acids that are mainly found in milk fat, beef and industrially produced food.

That sounds very mathematical at first. Essentially, it is about reducing industrial ready-made products such as frozen meals, canned goods, ready-made sauces and animal fats. The same applies to sugar and salt consumption. Salt should make up less than 5 grams and sugar less than 10% of daily calories. Even less sugar is even healthier. Ready-made products often contain a lot of salt and sugar. The amounts are always indicated on the packaging. It's worth taking a look before you buy. Overall, the diet should consist largely of fruit, vegetables, legumes, nuts and whole grain products.

Of course, these are average values ​​and nutritional recommendations must be adapted to the individual. Advice from a doctor or nutritionist can therefore be helpful. The good news is: a healthy diet is not particularly complicated or expensive. But it can be difficult to leave old habits behind and resist the little temptations in everyday life. It is better to avoid chips, cookies and potato chips.

Never too late to change your diet

Most people eat the way they remember it from their childhood. How does a change in diet affect health later in life? A large cohort study investigated this question. Cohort studies observe people with a certain characteristic (risk factor, stress or certain behavior) compared to people who do not have this characteristic. In this way, connections can be made between this characteristic and the occurrence of diseases. 

In this 2017 cohort study, 48,000 women and 26,000 men were examined to see how a change in diet affected their health in the following 12 years. Switching to a healthy diet was proven to increase their life expectancy - and the longer the healthier diet was maintained, the longer they lived. This makes it clear that every year of healthy eating habits counts. A careful diet is worth it.

Making healthy eating sustainable

The health of our planet is closely linked to our own. Climate researchers and medical professionals from different disciplines are moving these fields ever closer together. The common research field is called "Planetary Health". Nutrition plays a key role in this. It should of course be healthy for people. In addition, sustainable interaction with the ecosystems is sought, thus securing our livelihood on earth in the long term. 

For example, food waste: around a third of food is thrown away worldwide. On average, every German citizen throws around 78 kilograms of food in the trash every year. But far too much food is also thrown away in agriculture and in retail, for example because it is not looking good enough. 

What we can do: If you plan your shopping well, you have already won a lot. It is best not to go shopping when you are hungry and first take a look in the fridge and pantry so that we can choose food more carefully. In restaurants, we ask for leftovers to be packed up for us and at home we freeze them or use them to create a new dish the next day.

Status of sustainable nutrition research

Planetary health research is still in its infancy, but the respected EAT-Lancet Commission wrote a comprehensive statement on the subject in 2019. This takes into account hundreds of studies from all relevant disciplines. The result: unhealthy and sustainably produced food poses a high risk to people and the planet. In addition to the 820 million people with inadequate access to food, there are many whose unhealthy diet leads to illness and premature death. In addition, global food production poses the greatest threat to our ecosystems.

The urgent need for action becomes clear when current nutritional trends are projected into the future. Forecasts assume that the population will grow to 10 billion people by 2050. Current food production increases greenhouse gas emissions, the loss of biodiversity, poor land use and huge water consumption. A change in diet is also crucial to achieving the Paris climate goals.

Hand in hand: WHO goals and planetary health

The planetary health goals largely coincide with those of the WHO. A healthy and sustainable diet consists of an appropriate calorie intake with numerous plant-based foods, only small amounts of animal products, unsaturated rather than saturated fats and as little sugar, convenience foods and refined grains such as white flour as possible. The vegan diet is also widely discussed in this context.

In order to achieve the planetary health nutrition goals, the consumption of unhealthy foods such as red meat and sugar must be reduced by at least 50% and the consumption of healthy foods such as nuts, fruit, vegetables and pulses must be increased by 100%. These are average values. In wealthy countries, eating habits are significantly more harmful to the climate and therefore require greater adaptation.

This change in diet would bring great benefits to one's own health. Annual deaths would be reduced by 11 million - a reduction of around 20%. The authors also see an adjustment of agricultural practices and less food waste as essential. Further studies will follow. Now it's our turn.

If you are also interested in the topic of nutrition during pregnancy, please visit our article on nutrition during pregnancy and our article on foods that are prohibited during pregnancy.

The contents of this article reflect the current scientific status at the time of publication and were written to the best of our knowledge and belief. However, the article cannot replace medical advice and diagnosis. If you have any questions, contact your general practitioner.