Need help losing weight

Since I left university, I have been putting on more and more weight every year. The problem for me is that I used to be very active at uni, going cycling at weekends, playing badminton and tennis etc. Now that I have a full time job (in an office), I am not burning off enough calories. What makes the situation worse is the fact that I can't help myself from snacking during the day whilst at work. And by the time I finish work (usually around 6-7pm), I don't have the energy to excercise. Has anyone else been in the situation, and managed to turn themselves around? My main problem is lack of motivation to excercise, but also the fact that these snacks are so tempting for me when I am in a work environment.

i also work in an office and although im not worried about my weight i can understand the lack of motivation for exercise. do you live close enough to walk to work? do you work in a block where there are stairs and a lift. if so take the stairs rather than the lift. even if you just do that in your lunch break. or go for a brisk walk in your lunch break, that way you get exercise and some fresh air. what do you snack on? try taking fresh fruit to snack on rather than say a choc bar. hope this little bit helps