Possible explanation for the often lack of satiety found in obese people
German researchers have discovered a possible explanation for the often lack of satiety in overweight people. They found that in the brain of obese people, the production of energy from glucose (sugar) is greatly reduced. Another finding: There is a parallel between overweight and depressed people.
Why some people don't get full
Not only in Germany, obese people are often stigmatized and marginalized. Obesity has long been a common disease caused by many factors. Some of them have little or no influence. So overweight people often have a lack of satiety, which, according to scientists, can be explained, among other things, by a sluggish metabolism. Certain gut bacteria can also be to blame for excess pounds, as French researchers reported. Scientists from the Section for Psychoneurobiology at the Center of Brain, Behavior and Metabolism (CBBM) at the University of Lübeck have now found another possible explanation for the often lacking satiety of overweight people.
The number of overweight people is steadily increasing
According to current estimates, obesity affects around 2.2 billion adults worldwide, of whom 650 million suffer from its extreme form - obesity, according to a statement by the University of Lübeck.
According to the World Health Organization (WHO), obesity affects 340 million children in the age group between five and 19 years and 41 million children under the age of five.
In Germany alone, the number is around 60 percent of the population, now more men than women.
Current therapy programs for weight loss are based on diet plans, changes in diet, calorie calculators, sports programs etc. and, based on current knowledge, are not effective in the long term.
In the long term, in the majority of cases they lead to weight gain again, often even beyond the initial situation (so-called yo-yo effect). The number of overweight people is therefore continuously increasing.
Disorder of energy homeostasis
Researchers see an explanation for this development in a disturbance in energy homeostasis in the brain.
A team led by Prof. Kerstin Oltmanns from the University of Lübeck was able to prove in 2010 that there is a connection between increasing body weight and reduced energy content in the human brain.
The cause of the lowered energy status was completely unclear. One only knew that a high cerebral energy content triggers feelings of satiety. Overweight people often report that they do not perceive satiety.
Changes in brain energy status were examined
An interdisciplinary working group of the Lübeck section for psychoneurobiology, led by the graduate psychologist Ewelina K. Wardzinski and Prof. Oltmanns, has now in a current study in obese and normal-weight men by intravenous glucose infusion the blood sugar content - and thus the sugar supply for energy production in the brain - experimentally increased and changes in brain energy status examined.
This was done using 31P magnetic resonance spectroscopy, a method that very few research centers worldwide have.
In the normal-weight group, the brain energy content rose immediately after glucose administration, whereas there was no change in the obese study participants.
Only after a strong increase in blood sugar through the infusion did a slight increase also occur in the brains of the overweight study participants.
The researchers recently published their results in the journal “Metabolism”.
Obesity as a psychoneurobiological disorder?
"The results of this study show that there is a disruption in energy production in the brain of overweight people," explains psychologist Wardzinski.
"This disorder may explain the chronically reduced cerebral energy status in those affected and also why overweight people often do not feel full. Then the brain starves, so to speak. "
Interestingly, there are parallels to mental illnesses that affect mood and feelings with regard to the reduced brain energy level.
People with depression also show reduced brain energy levels. Similar to mental illness, behavioral therapy instead of diet plans appears to be successful with obesity.
A behavior therapy learning program developed especially for overweight people leads to an improvement in satiety, a reduction in food intake and thus weight loss, as the first interim results of an ongoing study show.
"Apparently the psyche, brain energy metabolism and body weight regulation are closely related, which has to be taken into account if you want to lose weight permanently," says Prof. Oltmanns. (ad)