Alan is somewhat surprised that he has gained a couple of pounds since coming to college. he has never had a weight problem. in high school, he was active every day in school sports. alan admits that his eating habits probably are not as good as they should be. still, he eats only three meals a day and a snack at night. he does not snack between meals, because he does not get hungry. alan is not involved with any college sport, but he does play basketball with his friends occasionally. he also has a part-time job and a full course load. alan thinks he is more active in college than when he was in high school. in fact, he often feels rushed going to classes because of the distance between classroom buildings and the fact that most of his classes are on the third or fourth floor and he has to wait to get an elevator. the most likely cause of alan's weight gain is