One in every five people across the globe dies of causes associated with a poor diet.

A new study published in the scientific journal "The Lancet" reports an overconsumption of red and processed meats, salt and sugar and not enough fruit, vegetables and legumes are to blame for damaging our hearts and causing cancer.

Our daily diet, researchers say, is a bigger killer than any other risk factor, including cigarette smoking. 

Eleven million deaths globally in 2017 can be attributed to cardiovascular disease, which is often caused or made worse by obesity and poor diet — in particuar an overconsumption of salt.

Stefan Lorkowski, a German researcher who contributed to "The Lancet" report, sat down with DW to nut out the findings of the paper.

Read more: Poor eating habits killing millions globally, study says

DW: When it comes to unhealthy diets, we often hear of eating junk food, alcohol consumption and cigarette smoking being our biggest concern when it comes to our health. In your study, what did you find a dangerous diet consists of?

Stefan Lorkowski: This clearly depends on the country you look at. It is quite well-known that the dietary habits in developing countries are different than in well-developed industrialized countries, although they have some similarities.

For example, whole grains are eaten the least in almost all countries. In developing countries, the decision often depends on availability and someone’s income. If you have a low income you don't buy vegetables, you don't buy meat; instead, you buy cheap and often starch-rich foods. In the more industrialized countries, we have a somewhat different situation because we have enough money to spend on food, but we also eat foods which are low in fiber, but rich in refined starch and fat, and calories as well.

An important issue is also the amount of food we eat. That means the calories. We’ve been able to see a steady increase over the years in the BMI [body mass index] worldwide. 

You mentioned the energy intake and how much people are eating of certain foods. But what are people missing when it comes to their diet? What aren't they eating that they really should be getting more of?

So, a serious issue seen in our study is the low intake of fiber. We do not eat enough wholegrain products. We prefer fast foods which consist of refined starch and fat as well. These foods are usually low in fiber and also low in micronutrients and trace elements. Our intake of sodium is generally much too high. Salt is a trigger in our diet. We like sweet and salty food and our major issue is that we become used to the taste. Next, as we increase in age, we likely need more salt and more sugar to find something tasty. This may lead to an increased intake as we age.

As it is mentioned in our study, more than 50 percent of all the deaths are a result of not eating enough whole grains and fruits, and a too high intake of sodium.

In your research you say that Uzbekistan tops the list of countries with the highest risk of diet-related deaths. Israel the smallest, Germany rates somewhere in the middle. What did you find out about Germany?

One issue, and this is not considered in our study, is the calorie intake. More than 50 percent of Germans are obese. This is a recent figure from [Germany’s] federal statistics office. So, we definitely have a problem with obesity and its consequences such as diabetes mellitus.

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Beside calorie intake, in Germany, we don’t eat enough foods of plant origin, such as fruits and vegetables, but consumption of meat and meat products is too high. This means that we don’t eat enough whole grain and other fiber-rich foods. We’ve known this for many years. Some years ago, we had a country-wide representative survey, the German National Nutrition Survey II, which revealed that we eat less than 20 grams of fiber per day, although it’s recommended to eat more than 30 grams. And we know from a recent study published in The Lancet that whole grain and fiber intake is a major driver in preventing total mortality, cardiovascular diseases, diabetes mellitus type 2 and colorectal cancer.

This is a real issue because people prefer to eat products which contain refined starch and added sugar instead of eating more whole grain products likely also because these products are more expensive. On the other hand, if you eat more whole grains you also usually have a better satiation and eat less.

Finally, we know from past surveys in Germany that almost half the carbohydrates we eat are sugars. This is another big issue because we know that sugars are responsible for an increased risk for cardiovascular diseases and diabetes.

How were you and your colleagues able to analyze a country's eating habits? What method did you go through to collect this data?

The Global Burden of Disease Study collects data from different sources. But, one typical way of collecting data are so-called food frequency questionnaires, or 24-hour recalls, which are used to find out what people have eaten over the last day or past few days. This is a difficult thing because if I ask you what you ate yesterday you will most likely find that quite difficult. But this is the best approach we have today.

Next, if you look at collecting data at the national level this is also something difficult because people in the south of Germany eat different foods than in the north, east and west. So, we have no ideal tools available now and we need to develop better ones.

You mentioned there that within Germany people eat differently in the north to the south, east and west. How are you able then to compare developing countries where the food supply and quality is oftentimes an issue with countries, say, in Europe, like Germany, where quality and supply of food is somewhat better?

It is important to note that the idea of the Global Burden of Disease Study is not to compare dietary habits between countries.

Indeed, the reasons why people suffer from certain diet-related diseases are different from country to country. If you look at developing countries, or at countries with a very low socio-demographic index, people don’t eat enough vegetables and fruits because people are too poor to buy them, or these foods are not available. If you don't have money you can't buy meat or high-quality milk products, you just try to get enough calories. This means, in these countries people often have a diet rich in starch and low in fibers and micronutrients just because people eat a lot of rice, corn and so on. In contrast, micronutrient supply in well-developed countries such as Germany is likely better, but our diet is also unbalanced as intake of vegetables, whole grain foods, added sugar and refined starch as well as meat and processed meat is not appropriate.

The Global Burden of Disease Study provides a tool to quantify health loss from risk factors such as an unbalanced diet and to help policymakers understand the true nature of their country’s health challenges; this information can then be used to improve the health situation in their countries.

Critics say your paper puts too much emphasis on individual components, be it sugars, fats, red meat, processed meats, rather than an overall diet. What do you say to that?

For sure this is an issue. We know that we cannot explain the effect of a diet on our health just by looking at the relation of nutrients to each other, or by looking on single nutrients and components. Next, people don't think in nutrients, people don't buy nutrients — they buy food products. But as scientists we need to know which components in our diet are the driving factors.

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However, the components studied here characterize the quality of a diet quite well. Nevertheless, the Global Burden of Disease Study collaborators are continuously improving the process of data analysis, and we will likely present even better data in future iterations of our study.

Stefan Lorkowski is a professor at the department of Nutritional Biochemistry at the Insitute of Nutrition of the Friedrich Schiller University in Jena, Germany. He contributed to the "Health effects of dietary risks in 195 countries, 1990-2017: a systematic analysis for the Global Burdan of Disease Study 2017" paper which was publised in science journal 'The Lancet.'

The interview with Professor Lorkowski has been edited and condensed for clarity.