It is known worldwide that malnutrition is a very common problem in the developing countries. Does this also apply to the industrialised countries? Yes, malnutrition is also a problem in the industrialised countries. International studies show that until up to 50 percent of the elderly people are at risk of malnutrition, depending on their setting and which definition of malnutrition is used. What do you mean by setting? The setting is the local environment of the affected people. It refers to whether or not they live in a nursing home, live at home, or have begun a period of hospitalisation. But now I would like to know in which setting the highest prevalence of malnutrition occurs? If you compare the different settings with each other, you will find the highest prevalence of malnutrition in the hospital setting. About every third patient there is at risk of developing malnutrition. If the hospital stay is due to elective operations, for example, i.e. planned interventions, then the prevalence drops back to down to about 20 percent. If you enter the nursing home setting, you also find a prevalence of about 20 percent. The prevalence is even lower among elderly people living at home, at approximately five percent. These high percentages clearly illustrate the problem of malnutrition. But what does malnutrition actually mean? Malnutrition is defined as a dietary condition that results from the inadequate intake of nutrition and that is accompanied by physical impairments and weight loss. If an insufficient nutrition supply is present, the body draws upon its energy reserves, primarily on its fat reserves, but also on reserves of the lean body mass, such as the musculature, bone mass, or organs. For this reason, malnutrition can lead impaired organ function. However, no definition of malnutrition has been generally accepted, although professional societies have been very keen to develop one. And what are actually the causes of malnutrition? There are many different causes of malnutrition. These especially include diseases in which malnutrition becomes a side effect, such as primarily tumour diseases but also lung diseases like COPD or liver diseases such as liver cirrhosis and even dementia. But how are malnutrition and dementia related? Yes, people with dementia often have a poor appetite. This means that they eat less and often forget to concentrate on their food. In addition, their behaviour while eating is often abnormal. For example, they no longer know what to do with the cutlery, how they should begin eating, or what they should do with the food. They often chew on one piece of food for a long time without swallowing it. They play with the food. An additional problem encountered with dementia patients is that they are often restless and wander or walk around. This increase their demand for energy. There are a multitude of factors that need to be taken into account. Are there other causes? Yes, there are many more causes of malnutrition. With respect to older people, depression can have a particularly strong effect or polypharmacy, i.e. the intake of several drugs. But also emotional, psychological experiences and traumatic events can be causes, such as the loss of a spouse or the act of a spouse being relocated to a nursing home. And then there are other factors, such as swallowing disorders, chewing problems and inappropriate prostheses that also lead to the ingestion of an insufficient amount of food. If a person becomes malnourished, what effects can we expect? On the one hand, there are negative effects on the victims themselves. These include increased rates of infections or complications or also delayed wound healing which in turn increases the risk of decubitus. There are also many functional consequences, such as reductions in muscle mass, muscle strength (i.e. sarcopenia) but also in mobility and an accompanying increase in dependency on nursing care. On the other hand, there are negative effects on the health system. These are mainly represented by the increased cost burden. We know from international studies that malnourished people have longer hospital stays than people who are not malnourished which, of course, increases the costs. And malnourished people go twice as often to the hospital as people who are not malnourished.