First, cut down on Soda... Start drinking more water, and taking multi-vitamins.
When you eat, give youself smaller portions, and don't eat the entire meal. Leave a few bites left on the plate. (Only eat to satisfy your hunger, not to get full).
I would only suggest 1 hour of workout, and do a multitude of different exercises, like treadmill, weights etc.. but, focus alot on cardio stuff, to start burning some of the built up calories.
Do this for a couple of weeks, and you'll notice a significant difference. Then start cutting soda and sweets out completely, and drinking more water.
Start eating more vegetables, and fruits, and lean red meat. Try to cut out "grain" from your diet.
Try it out, I bet you will see a big difference in how you feel and how you look.
Also, when you are awake, try to keep your stomach muscles tightened as much as you can. After a while it will become habit, and it won't become a "gut".
