This article suggests that sitting still increases hunger. US researchers carried out a study where they monitored the appetite of a group of people who were asked to be active or inactive for day at a time. On the days when they were inactive the people were more hungry. Whilst the results are preliminary the study suggests that exercise decreases appetite whilst sitting still boosts it. I’m not sure how much truth there is in this but I defiantly eat more if I am bored and have nothing to occupy me.