Acute Exercise Increases Attentional Bias Towards Food Cues

Abstract

Although exercise is a common weight loss strategy, the amount of weight loss resulting from exercise training is often less than expected. This is often attributed to exercise promoting greater energy intake, resisting the exercise-induced negative energy balance required for weight loss. Prior research on how exercise can influence hormonal mediators of appetite offer conflicting results, with some demonstrating longitudinal exercise increases the satiety response to a meal and changes in hunger hormones do not predict weight loss. Research on other underlying mechanisms working to promote energy intake during exercise is scarce. PURPOSE: To determine if acute exercise influences attentional bias towards food cues. METHODS: Thirty (30) participants (BMI ≥ 25, aged 18-50 years) completed the Dot-Probe task before and 15 minutes after a bout of aerobic exercise where they expended an estimated 500 kcal and before and after a 60-minute bout of television watching (sedentary condition) on separate sessions. Sessions were separate by one week and order was counterbalanced across participants. The Dot-Probe task uses an eye-tracking device to measure the amount of time (ms) participants spent fixated on image pairs projected on a computer screen. Images included either highly appealing food (critical task stimuli) or neutral (non-food) images. Images were presented for 3,000 ms. A yellow dot appeared on either side of the screen in place of one of the previously presented images. Participants responded as quickly as possible to indicate which side the probe appeared by pressing a corresponding computer key. Mean fixation time (amount of time looking at each image) was recorded in ms. RESULTS: A condition (exercise vs sedentary) by time (pre vs post) interaction (p = 0.001) was observed where the percent of time fixated on food cues increased from 48.3% pre to 56.6% post-exercise while fixation percent changed from 50.6% pre to 49.7% post-sedentary. CONCLUSION: Acute aerobic exercise increases the environmental salience of food cues, which may increase the motivational drive to eat and resist an exercise-induced energy deficit. Attentional bias training has been successfully used to change eating behaviors and may represent a novel adjunct therapy to increase the success of an exercise for weight loss intervention.