亀本 佳世子

Acute land-based high-intensity exercise has been shown to alter food reward. However, it remains unclear regarding the acute effect of different exercise intensities on food reward. Therefore, we examined the response of food reward to high- and low-intensity treadmill exercise in healthy young men. Twelve healthy young men (aged 22.8 ± 2.0 years, mean ± standard deviation) completed three, half-day laboratory-based trials (i.e., high-intensity exercise, low-intensity exercise and control), in a random order. In the exercise trials, the participants performed a 60-min exercise (from 09:30 to 10:30) at a speed eliciting 70 % (high-intensity) or 40 % (low-intensity) of their maximum oxygen uptake and then rested for 90 min. In the control trial, participants sat on a chair for the entire trial (from 09:30 to 12:00). Food reward was measured at 09:20, 10:30 and 12:00. Relative preference for high-fat foods was not altered among the three trials. The relative preference for sweet foods was higher in the high-intensity exercise trial than the low-intensity exercise (mean difference: 15.3; 95 % CI: 2.53-28.14; p = 0.007) and control (mean difference: 14.6; 95 % CI: 2.37-26.80; p = 0.007) trials at 10:30 (i.e., immediately after exercise). Greater relative preference for sweet relative to savoury foods was observed following an acute bout of high-intensity run. These findings suggest that high-intensity treadmill exercise may shift taste preference toward sweet foods in young healthy men.

Acute moderate- to high-intensity exercise, primarily aerobic exercise, has been reported to decrease food reward in brain regions via the hedonic pathways and reduce preference for high-energy or high-fat foods. However, studies examining food reward responses to acute exercise have been limited to measuring food reward only after exercise and less frequently before and after exercise. Therefore, the changes in food reward in response to acute exercise remain unclear. This study investigated the effect of acute running on food reward in healthy young men. Fourteen young healthy men (mean ± standard deviation, age; 23 ± 2 years, body mass index; 21 ± 2 kg/m2) completed two trials (i.e., exercise and control) in a randomised, crossover design. Participants performed a 30-min running bout at 70% of maximal oxygen uptake or sitting rest before and after food reward evaluation with a computer-based food choice behaviour task tool. Food reward was assessed for foods varying in fat content and sweet taste, and there were four assessment parameters: explicit liking, explicit wanting, implicit wanting and frequency of choice of each food category (relative preference). Explicit and implicit wanting, and relative preference for high-fat relative to low-fat foods were reduced after the exercise trial compared to the control trial (trial-by-time interaction, all p ≤ 0.02). Implicit wanting and relative preference for sweet relative to savoury foods were increased after the exercise trial compared to the control trial (trial-by-time interaction, all p ≤ 0.003). These findings indicate that moderate-intensity acute running alters the reward bias away from high fat towards low fat foods and away from savoury towards sweet foods in healthy young men.