One great trick, I probably saw it on lifehacker or similar, is to phrase your decisions in terms of priorities - i.e., when choosing to do activity X (TV, long lunch, etc.) instead of Y (gym, run, etc.), consider that you're saying, "no, X is a higher priority for me than Y right now." It's cheesy, but it help keep you focused.
Yes - bringing a home-made lunch saves a ton of money, and is much easier to portion-control with. Don't eat snacks at work (supply yourself with healthy alternatives if need be).
Instead of an hour lunch break, take an hour gym break to a nearby gym, or work with your supervisor for a flex hour instead of a lunch break, show up an hour later (and use that to go to a gym on your way in). You'll be *amazed* at the increase in your afternoon productivity by going to a gym in the middle of the day, instead of stuffing yourself at the nearest lunch spot.
Walk/Run/Bike to or from work - only works if you have access to a shower facility or public transit for one-way commutes at work
Join a gym, *hire a trainer*, set a schedule. I went to the gym 3x/week for 2 years, slowly lost 5 pounds. Added a trainer, lost another 5 pounds ... in 3 months.
It sounds like the company cares about health, which is a great start - getting access to shower facilities at work really opens up a lot of possibilities, so investigate some options there.