A study by a team from the German Diabetes Research Center demonstrates that the brain's response to the hormone insulin adapts to short-term changes in diet even before weight gain occurs. This ultimately contributes to the development of obesity and other secondary diseases.
The findings are based on an experiment with 29 average-weight men. The first group maintained their normal diet, while the second group was given an additional 1,500 calories. The extra calories came from processed and high-calorie snacks, such as chips and chocolate bars. The experiment lasted five days, after which the second group returned to a normal, balanced diet.
Before and after the experiment, all volunteers underwent MRI and lab tests. The results were disappointing. First, the second group showed a significant increase in liver fat. Second, the scientists recorded decreased insulin sensitivity—this effect persisted even a week after returning to a normal diet.
"Previously, this effect was observed only in obese people. Now, for the first time, we see that even short-term negative changes in the diet of healthy people cause significant changes in the brain. Thus, the brain may contribute to the development of obesity, diabetes, and other diseases," the authors concluded.
In another study, scientists discovered that fat cells retain the memory of obesity for a long time. They were found to retain this memory even after dramatic weight loss and long-term maintenance of normal physical fitness.
