More brown body fat as a contributor to obesity
Why can some feast to their hearts' content without the calories being reflected on the scales? Scientists at the Technical University of Munich (TUM) have found one of many possible explanations for this phenomenon. Some people have particularly high amounts of brown fat, which is very metabolically active. Overall, the proportion of brown adipose tissue according to the current study is significantly higher than expected.
White fat makes up the majority of body fat and is responsible, among other things, for storing excess food energy. In contrast, energy is converted in the form of thermal energy in brown adipose tissue. It mainly sits in the neck area, on the sternum and on the spine. In young children, the brown fat ensures that the body temperature is maintained, since the surface of the body is large and the muscle mass is still low. So far, it has been assumed that it declines in adolescence and is barely present in adulthood.
In order to investigate the brown fat in more detail, the Munich scientists had evaluated almost 3,000 PET scans of 1,644 patients. PET stands for positron emission tomography and is used in cancer medicine. With this method, metabolic processes in the body can be made visible. Brown adipose tissue absorbs a lot of sugar, and this activity is reflected in the scans. The analysis of the data showed that the mass of brown fat is three times larger than assumed. This result is also interesting for drug research, since some drugs for obesity and diabetes activate brown adipose tissue. These preparations could therefore have a stronger effect, the authors write in the "Journal of Nuclear Medicine".
Another result was that the proportion of brown fat does not appear to be the same for everyone. Previous studies had previously shown that brown adipose tissue was more active in women than in men. The brown fat was also more active and its proportion higher among younger people. Active brown fat was far more common in about five percent of the test subjects than in the general population, which leads to a higher energy turnover and thus a lower risk of being overweight. This interesting field of research will continue to occupy science. The background has not yet been clarified. It is believed that certain signaling factors affect kidney and brown fat at the same time.
Heike Kreutz, respectively