How exactly does exercise reduce belly fat?
A recent study investigated a new signaling molecule, interleukin-6, that may play a crucial role in regulating exercise-associated loss in belly fat.
Obesity, defined as an excess of body fat, can increase the risk of several medical complications, including diabetes and cardiovascular disease. Moreover, excessive belly fat can worsen health outcomes, result in low self-esteem, and has an overall negative impact on a person’s quality of life. Clinicians and health care providers recommend that individuals eat a healthy, balanced diet and exercise regularly to maintain appropriate body weight and fat content.
Underlying mechanisms of how exercise reduces belly fat is unknown
Despite being commonly recommended, the underlying mechanisms by which physical exercise reduce belly fat is unknown. Some researchers believe that epinephrine, a hormone increased following exercise and responsible for the ‘fight-or-flight’ response, plays a critical role in fat reduction. Another molecular that increases in the body following exercise is Interleukin-6, an important signaling molecule that plays a role in energy metabolism and fat breakdown.
In a recent study in Cell Metabolism, Wedell-Neergaard and colleagues investigated the potential role of interleukin-6 signaling on exercise-related belly fat reduction. A total of 53 abdominally obese participants were recruited for the study and randomly divided into two groups; one receiving tocilizumab and the other receiving saline control.
Tocilizumab is a interleukin-6 blocker that is commonly prescribed for the treatment of rheumatoid arthritis. The two groups were further subdivided into 2 groups, one of which underwent a weekly 45-minute bicycle exercise program while the other had no exercise. At the beginning and end of the study, each participant underwent magnetic resonance imaging (MRI) to assess belly fat tissue mass.
Molecule interleukin-6 may play a crucial role in the loss of stomach fat
In the saline-administered group, individuals that underwent the exercise program had an 8% reduction in belly fat, compared to those that had no exercise. However, this exercise-dependent reduction in belly fat was completely abolished in participants that were given the interleukin-6 blocker. In fact, participants that were administered tocilizumab had higher levels of total and bad cholesterol, compared to those individuals that were given saline control.
In summary, these findings seem to suggest that interleukin-6 plays a crucial role in the exercise-associated loss of belly fat. It is well known that patients with obesity-associated complications like diabetes and cardiovascular disease exhibit significant metabolic dysfunction.
Future research will investigate if injections of interleukin-6 will reduce belly fat
It would be interesting to investigate whether interleukin-6 plays a role in mediating metabolic changes during these diseased states. The authors of the study plan on conducting further studies to investigate whether direct injection of interleukin-6 can reduce belly fat. This research could have significant implications for obese individuals by providing novel ways in which to regulate body fat. In the meantime, however, researchers and clinicians recommend that individuals exercise regularly and adopt a balanced diet to improve their health.
Written by Haisam Shah, BSc
Reference: Wedell-Neergaard, A. S., Lehrskov, L. L., Christensen, R. H., Legaard, G. E., Dorph, E., Larsen, M. K., … & Ball, M. (2018). Exercise-Induced Changes in Visceral Adipose Tissue Mass Are Regulated by IL-6 Signaling: A Randomized Controlled Trial. Cell metabolism.
