Being slim is healthy… or is it?


Obesity leads to illness. A widely accepted fact today, but this has not always been the case. In the post-war years, physical corpulence was still regarded as a sign of prosperity. But this was only until obesity and the emergence of cardiovascular diseases was first scientifically linked. A study published in the US in the early 1950s showed that overweight people had a life expectancy of three years less than those with "normal" bodyweight. What is normal and what is not was determined by researchers according to the so-called Body Mass Index (BMI), i.e. the measure for the assessment of the body weight of a person in relation to their body size. According to the classification of the German Society of Nutrition (DGE), the ideal BMI lies between 19 and 24 for women and between 20 and 25 for men. Everything below these figures is classified as underweight, above means overweight. A BMI of over 30 can be referred to as obesity. This brought on a change in the ideal of beauty. Slimming and fitness campaigns are en vogue ever since. Today, a whole generation lives according to the guiding principle "the thinner, the better". But recently it has become clear that "better" does not necessarily mean "healthier".

An increasing number of studies have concluded that chubby people can actually be healthier, fitter and have a higher life expectancy than lean people. A study from the US, with over two million participants, showed that people who are slightly overweight have a total mortality rate of up to 6% less than normal people, meaning that within a defined population and a defined period of time, 6% less overweight people have died than people with normal weight (irrespective of the cause of death). German researchers also found that lean patients in intensive care units survive less frequently than overweight patients. A possible explanation for this is that slightly overweight people facing diseases such as cancer or infections are able to fight these pathogens off with more resistance.

On top of that comes the fact that people who are overweight have a higher relative stress resistance and are able to better deal with psychological pressure. Recent studies also indicate that people who carry a few extra kilos not only live longer, but are also less likely to suffer from Alzheimer's and Parkinson's disease than lean people.

As the sole determinant of obesity, the BMI has thus apparently been outdated. The BMI also has another major flaw: it does not take the composition of the body mass in consideration and doesn't dissociate between fat and muscle tissue. This means that people who do a lot of exercise can have a BMI reflecting that of an overweight person. The simple explanation: muscles weigh more than fat. However, these people may be healthier than those who have a BMI of 22 and do not exercise.

Another determining factor is the fat distribution in our body: Belly fat is dangerous because it is shown to increase the risk of heart attacks, strokes and arteriosclerosis. However, in this context, fat around hips, buttocks and thighs are reasonably harmless. Furthermore, unhealthy fat is sometimes not visible from the outside. Hidden body fat on internal organs, e.g. the liver, can make you ill and lead to diabetes - so slender does not necessarily mean healthy. This is because even slim people can have too much body fat with lack of exercise. Another phenomenon of our time: the risk group of the so-called "slim patients".

And then there are our genes: researchers recently looked at the heredity of 76,000 people. The astonishing result is that one and the same gene on the one hand makes for a low body fat percentage -but is linked on the other hand to promote the development of cardiac diseases and diabetes. Thus some people a have higher potential risk of developing such a disease, whether they are thick or thin. The researchers warn, however, not to make the genes solely responsible for our health. Although some are more susceptible to certain diseases than others, the lifestyle we lead also plays a major role.

As with so often, health is multi-dimensional. If we want to be healthy, we have to make a few simultaneous adjustments - diet and exercise are the most important factors with the greatest impact on our health.

Thin people can therefore be sick more often than the more corpulent ones. People who are a little overweight are by no means automatically sicker - on the contrary: sometimes even more resistant.