According to a new study, researchers believe that changes to a central nervous system factor are responsible for weight loss during aerobic exercise. In the study, three months of aerobic exercise decreased body fat and calorie intake in overweight and obese people.
While this isn't the first time that aerobic exercise has been linked to weight loss, it is likely the first time that the central nervous system has been pinpointed as the reason for the loss.
A research team at the University of Chile Clinical Hospital in Santiago, led by A. Veronica Araya, MD, assistant professor, showed that decreased food intake and reduced body mass index (BMI), a measure of body fat, were linked to increased levels of a protein called "brain-derived neurotrophic factor", or what we'll call BDNF. Its main role is promoting the growth and survival of nerve cells, according to the authors.
However, this new evidence shows that BDNF also is also related to obesity and metabolism. The authors speculate after this study that it could suppress appetite. I see this work as potentially leading to new types of weight loss drugs.
The team evaluated blood levels of BDNF before and after a three-month program of aerobic exercise in 15 overweight or obese men and women. The seven men and eight women, ages 26 to 51, worked out on a treadmill and bicycle. They were asked about their calorie intake and told to continue eating their usual number of calories. The participants were unaware that one of the study’s objectives was to evaluate changes in food intake.
At the end of the study, the subjects had decreased BMI, waist circumference, and blood pressure, the data showed. They also reported consuming fewer calories than at the beginning of the study. Over the three months, BDNF levels greatly increased. This higher the concentration of BDNF, the less the subject’s intake of calories and the greater the weight loss, the authors said.
Thus, it is possible that increases in BDNF suppress appetite.