Seven nutritional myths elucidated

What research knows today

17-Aug-2018 - Germany

This week in August promises hot temperatures and little cooling. Some people lose their desire for warm meals and sumptuous meals. But how healthy are the alternatives? Do fruit and food really make you fat in the evening? And are overweight people themselves to blame for their weight? "No," says Prof. Dr. Matthias Blüher, Head of the obesity Outpatient Clinic for Adults at the Integrated Research and Treatment Centre (IFB) AdiposityDiseases at Leipzig University Hospital. Obesity is a disease that is determined by many factors. In the interview, the physician talks about supposed healthy fruit snacks and research into the causes of obesity.

In summer we need fewer calories because the body uses less energy to cool down.
Prof. Dr. Matthias Blüher: That is not true. In situations of extreme heat or cold, our body's energy consumption is generally increased: we need more energy both during freezing and cooling. However, it cannot be assumed that there are different chances of losing weight in summer or winter. The only difference actually lies in eating habits: In summer, many typically eat lighter and lower-calorie meals, while in winter you tend to eat the classic winter bacon.

Especially at hot temperatures, many people rely on fruit snacks. You can eat as much as you like - fruit is always healthy.
Prof. Dr. Matthias Blüher: Unfortunately, this is not quite correct, because the dose also makes the poison in fruit. Fruits can also contain a great deal of calories and carbohydrates. A current example from research shows that fructose, which we increasingly find in fruit, can make a very significant contribution to the development of fatty liver.

Even if the temperatures have cooled down a bit: Dinner makes you fat.
Prof. Dr. Matthias Blüher: That is also true and not true. Again, it depends on how much comes on the table for dinner. It is assumed that the calories cannot be burned again in the evening, because then one goes to bed. Ultimately, however, there is no evidence at what time of day calories are more harmful to weight - the total amount you consume throughout the day counts. However, many people find it easier to do without food in the evening in order to reduce their weight. Scientific research has shown that people who eat breakfast regularly have a higher chance of losing weight.

With light products, on the other hand, you lose weight.
Prof. Dr. Matthias Blüher: Unfortunately, that is not true. In light products, sugar is often replaced by sugar substitutes. These substitutes can whet the appetite or have a direct effect on our intestinal bacteria. Light products can thus indirectly contribute to an increase in appetite and still not lose weight - even if the name promises otherwise.

Overweight and obese people are themselves to blame for their obesity.
Prof. Dr. Matthias Blüher: Not true. We now know, for example, that genetic factors play a major role in the development of overweight and obesity. Hormonal aspects and our social environment also cause the development of obesity. All these factors cannot be actively influenced by the individual.

Overweight people simply need to eat less and exercise more, then they already lose weight.
Prof. Dr. Matthias Blüher: Actually, that's true. Unfortunately, it has to be said that weight loss concepts based only on eating less and exercising more have failed in the long term. We only know part of the reason for this. It is very likely that our body will be able to defend a weight once it has been reached. Here different mechanisms interlock, which lead the body to want to return to its maximum weight again and again. These factors include, for example, the exhaustion of calories absorbed from food and the regulation of basal metabolic rate, appetite and satiation. We cannot consciously control these factors either.

Obesity is a disease and the causes of obesity are fully known to science.
Prof. Dr. Matthias Blüher: I can say yes to the first part of the thesis. We see obesity as a disease and are not alone - the World Health Organization also defines obesity as a disease. I must deny the second part of the thesis: We are still trying to fully understand the causes of obesity for individuals and at the social level. So far, we have only been able to establish a clear link between the defect of a gene and the development of obesity in a few individual cases.

Obesity research in Leipzig

Obesity research has been a focus of the University of Leipzig for many years. The Science and Humanities Council also attests to the location's outstanding competence in this area. In February 2018, the University of Leipzig submitted a full proposal for the Excellence Cluster "Understanding Obesity" in the Excellence Strategy of the Federal and State Governments. The project pursues an interdisciplinary approach that links medicine with the social sciences and the humanities. Because the causes and consequences of obesity are not purely a medical issue, but are embedded in our culture and society. Effective prevention and therapy strategies must therefore be developed and thought of in this context. The University of Leipzig presents the scientists and their research work behind the cluster application: From historians, bioinformaticians and physicians to communication scientists.

https://www.yumda.com/en/news/1156972/seven-nutritional-myths-elucidated.html