I currently weigh about 168, my lowest weight since college. I've lost about 30 lbs since Christmas, and cycling/bike commuting has played a big role. However, I had steadily gained weight for years, when I was also cycling a lot. I've managed to lose the weight by carefully tracking calories eaten and burned from exercising using a free on-line tracker called Lose It! Basically you enter in all of your personal data, set a goal for how much weight you want to lose over what time period, and LoseIt sets a calorie budget for you. The program automatically adjusts your budget lower as you lose weight because you need fewer calories. Long story short, I set my goal at losing 1 lb/week and have steadily lost weight at close to that rate since I started. I'm now in maintenance mode -- that is, simply trying to stay at my current weight.