Don't 'go on a diet' - change your diet.
Cut back or eliminate things like soda (even diet soda in my opinion). Eliminate the chips and cut way back on the fast food in general.
Replace unhealthy foods with healthier choices. Eat smaller portions. Think about what you put in your mouth before you put it in your mouth.
Try and eat a balanced diet including protein, carbs, and, yes, fat. You need them all.
You could track calories if you wanted to, and I found it a good way to figure out how I should be eating. There are lots of online calculators out there.
Drink lots (and lots and lots) of water.
Exercise is great, and necessary if you want to retain your muscle mass while losing fat, but it is the dietary side that will really lose the weight for you.
If you were exercising regularly but still eating poorly, chances are you wouldn't see much change.
Food is key.
I'm at work right now and don't have time to go into a lot of detail. Look around this site, read the sticky notes, find what will help you reach your goals.
Oh, yeah, set goals. Goals help us keep on track. Have both short-term (what do I want to accomplish this month?) and long-term (where do I want to get eventually?) goals.
And, keep in mind that a nice, healthy, safe and sustainable rate of weight loss is about 1% of your body weight per week. For you that's about 3 pounds.
Hope this helps.
