A single lap of running can lead to an increased response to food stimuli in parts of the brain associated with attention and reward expectancy, a new study has found that could open up ways to regulate appetite for weight loss.
Previous research has shown that the amount of food people eat is influenced by brain processes that are sensitive to changes in the body and the immediate food environment.
Studies have also shown that single workouts like running can temporarily suppress appetite.
Scientists have previously pointed out that the way we respond, both physically and psychologically, to the sight or smell of food — also known as “food cue reactivity” — affects appetite and the amount we end up eating eat, can influence.
However, the extent and process by which exercise immediately after exercise affects appetite is still unclear.
Researchers, including those from the University of Bristol in the UK, looked at whether changes in blood flow in the brain caused by exercise can affect how people respond to food.
The effect of running on blood flow to the brain and how this affects brain activity in relation to appetite was examined in the new study published in the journal Mapping of the human brain.
As part of the research, fMRI brain scans were performed on 23 men before and after 60 minutes of running or rest.
During the scan, participants were asked to look at three types of images, ranging from low-energy-density foods like fruits and vegetables, to high-energy-density foods like chocolate, to non-food items like furniture.
Researchers found that the volume of exercise suppressed the participants’ feelings of hunger.
However, it also increased the responsiveness of several parts of their brain to food cues.
The researchers also noted changes in blood flow in the brain after exercise, but these changes did not appear to affect reactivity signals to food stimuli.
This suggests that the changes in the way participants responded to visual food cues were independent of the overall changes in brain blood flow.
“Our results confirm that individuals feel less hungry during and immediately after an exercise session and provide some insight into the short-term impact of exercise on the brain’s appetite responses,” said Alice Thackray, co-author of the study.
Research confirms that the brain plays an important role in controlling appetite and food intake.
“The study provides a springboard for further work to more accurately and comprehensively characterize appetite responses to exercise. This, in turn, will allow us to better understand the role of exercise in preventing and managing unhealthy weight gain,” said David Stensel, another author of the study.