Summary: New research shows that a single session of running heightens the brain’s responsiveness to food-related cues, even though it can temporarily reduce how hungry people feel.
Researchers using functional magnetic resonance imaging (fMRI) found that running increased activity in brain areas involved in attention, anticipating reward, and episodic memory when participants viewed images of food. These neural changes occurred independently of overall shifts in cerebral blood flow (CBF), suggesting that acute exercise can alter appetite-related brain responses through mechanisms beyond blood flow variation.
This finding adds nuance to our understanding of how exercise, appetite, and food intake interact and may inform future strategies for weight management and nutrition guidance.
Key facts
- Running increased brain reactivity to visual food cues in regions tied to attention, reward anticipation, and memory, independently of changes in cerebral blood flow.
- Participants reported reduced hunger immediately after exercise, despite the brain showing heightened responsiveness to food cues.
- These results help clarify the complex relationship between acute exercise, appetite regulation, and potential implications for weight control.
Source: Loughborough University
A single bout of running increased reactivity to food cues in brain regions associated with attention, reward anticipation, and episodic memory, according to a study published in Human Brain Mapping.
An interdisciplinary team from Loughborough University, the University of Bristol, the University of Nottingham, the University of Leicester, and Waseda University (Japan) examined how a one-hour run changes cerebral blood flow and whether those blood flow changes influence appetite-related brain activity.
Participants viewed images during fMRI scanning that ranged from low-energy-dense foods (fruits and vegetables) to high-energy-dense items (chocolate), plus non-food objects such as furniture. The researchers compared brain responses before and after 60 minutes of running with responses before and after a resting session.
Although exercise temporarily suppressed subjective feelings of hunger, it simultaneously increased neural reactivity to food cues in multiple brain regions. Using arterial spin labelling to measure cerebral blood flow, the team also observed exercise-related blood flow changes in specific brain areas. Crucially, adjusting the analysis for CBF variability did not eliminate the exercise-induced increases in food-cue reactivity, indicating those neural effects were not driven solely by blood flow shifts.
Food cue reactivity refers to the physiological and psychological responses triggered by sensory exposure to food—such as seeing or smelling food—which can influence appetite and subsequent eating behaviour. Understanding how acute bouts of exercise affect this reactivity helps clarify why exercise can sometimes suppress appetite immediately while simultaneously increasing the brain’s sensitivity to food cues.
In the study, 23 healthy young men (average age 24 years, average BMI 22.9 kg/m2) completed fMRI scans before and after 60 minutes of running at about 68% of peak oxygen uptake, and on a separate occasion they completed equivalent scans after 60 minutes of rest. The design was randomized and crossover, so each participant served as their own control.
The running session produced higher CBF in grey matter, the posterior insula, and regions near the amygdala and hippocampus, while lowering CBF in the medial orbitofrontal cortex and dorsal striatum compared with rest. Despite these overall CBF differences, the exercise-induced increases in food-cue BOLD responses remained apparent after accounting for CBF variability.
Lead author Dr Alice Thackray, Senior Research Associate in Exercise Metabolism at Loughborough’s School of Sport, Exercise and Health Sciences (SSEHS), noted that the results confirm people feel less hungry during and shortly after exercise while also revealing short-term effects of exercise on brain responses related to appetite. She emphasized that further research is needed to determine how these neural changes translate to real-world eating behaviour and longer-term energy balance.
Professor David Stensel, Professor of Exercise Metabolism at SSEHS, said the study contributes to an ongoing debate about exercise’s role in appetite regulation and weight control. He highlighted that characterising brain and appetite responses to exercise more precisely will improve our understanding of how physical activity helps prevent and manage unhealthy weight gain.
Dr Elanor Hinton of the University of Bristol described the work as a successful collaboration that began as a pilot between research centres. She said the partnership produced robust findings and additional publications are forthcoming, underlining the value of multi-centre research in exercise neuroscience.
About this exercise and neuroscience research news
Author: Judy Wing
Source: Loughborough University
Contact: Judy Wing – Loughborough University
Image: Image credited to Neuroscience News
Original research (open access): “Exploring the acute effects of running on cerebral blood flow and food cue reactivity in healthy young men using functional magnetic resonance imaging” by Alice E. Thackray et al., published in Human Brain Mapping.
Abstract
Exploring the acute effects of running on cerebral blood flow and food cue reactivity in healthy young men using functional magnetic resonance imaging
Acute exercise is known to temporarily suppress appetite and change how the brain responds to food-related cues, but it is unclear how much exercise-induced shifts in cerebral blood flow (CBF) influence the blood-oxygen-level-dependent (BOLD) signal measured during appetite-related tasks. This study investigated how a single bout of running affects visual food-cue reactivity and whether such neural responses are driven by CBF variability.
In a randomized crossover design, 23 men (mean ± SD: 24 ± 4 years; BMI 22.9 ± 2.1 kg/m2) underwent fMRI scanning before and after 60 minutes of running (about 68% of peak oxygen uptake) and before and after a matched resting session. Pseudo-continuous arterial spin labelling scans assessed CBF before and across four repeat acquisitions after exercise or rest. BOLD-fMRI measured food-cue reactivity before and 28 minutes after each condition. Subjective appetite ratings were recorded before, during, and after exercise or rest.
Results showed that exercise increased CBF in grey matter, the posterior insula, and the amygdala/hippocampal region, while reducing CBF in the medial orbitofrontal cortex and dorsal striatum compared with control. No time-by-trial interactions for CBF were detected. Exercise produced moderate-to-large reductions in subjective appetite ratings but increased food-cue reactivity in the paracingulate gyrus, hippocampus, precuneus, frontal pole, and posterior cingulate gyrus. Crucially, adjusting the BOLD analysis for CBF variability did not markedly change the detection of exercise-induced neural responses.
In summary, a single session of running produced overall changes in cerebral blood flow that were not time dependent and increased food-cue reactivity in brain regions implicated in attention, reward anticipation, and episodic memory—effects that were independent of CBF variability.