The effects of exercise on appetite regulation

The effects of exercise on appetite and feeding responses can be influenced by several factors. Research has demonstrated that exercise-induced changes in appetite can be affected by ambient temperature. Furthermore, exercise intensity has also been shown to affect appetite and post-exercise caloric intake. The aim of this thesis was to investigate the impact of exercise at different ambient temperatures on appetite and energy intake (EI) in overweight and obese individuals. Furthermore, this thesis also aimed to examine the effects of high intensity exercise on both peripheral and central appetite regulation in lean healthy males. The findings from this thesis demonstrated that exercise in a cold environment (8°C) \nstimulated post-exercise EI in overweight and obese men and women compared with exercise in a neutral environment (20°C). Exercise in the heat (32°C) caused an increase in desire to eat 5 hours post-exercise compared with rest in the heat in overweight and obese individuals, however no further differences in appetite sensations were observed between trials. Findings from this thesis have also demonstrated that an acute bout of intense running suppressed neural activation within the orbitofrontal cortex and hippocampus in response to images of \nhigh-calorie foods compared with rest. Furthermore, pictures of low-calorie foods enhanced activation within the insula and putamen post-exercise compared with rest. These central regions are associated with regulating the rewarding properties of food, therefore these findings showed that high intensity exercise is capable of suppressing the rewarding properties of high-calorie foods whilst enhancing the rewarding properties of low-calorie foods immediately post-exercise. However, an acute bout of intense running enhanced central reward system activation in response to food cues compared with rest several hours after exercise. Therefore, the appetite suppressing effects of an acute bout of high intensity exercise could be short-lived.