Keep up the good work!

Assume you burn around 10 calories a minute for cycling. Your commute isn't even burning up your soda consumption, if the numbers posted earlier are correct. You may be burning about an extra 400 calories per day from cycling. Heavier people can burn calories at a higher rate than lighter people as they start to get fit. The "average" person who starts to cycle commute loses an average of 12 pounds, according to one source I read. It did not mention the time frame. For me, cycling 20 to 25 minutes twice a day, 3 or 4 times a week resulted in a 15 pound weight loss in about 4 months, then I stopped losing weight for almost a year. I had to really change the way I eat and ramp up the cycling a bit before I started going down again. Every pound since the first 15 pounds has been a struggle. However, after two years, my cycling abilities were amazing compared to when I started. Leg muscle developement is noticable. I may weigh 20 pounds less now, but I suspect I have 30 pounds of less fat, due to adding muscle mass as a replacement of fat. I don't really get that short of breath anymore, but my legs still hurt after every decent cycling session (10 miles of heavy exertion or 25 plus miles of normal exertion).

Don't worry about weight loss right now. Just do the cycling thing. Believe it or not, you will come to associate the leg muscle burning with the just rewards of healthier living, and come to see it as a sign of a job well done. You get incredible benefits from cycling right away, but it takes years to develope peak cycling abilities, especially the older you get and the more out of shape you are. Don't let the early phase discourage you. By the end of this year you won't believe the differences, and by next year you will be amazed. Eat normally for now, or just a modest reduction in calories. Later, you can start cycling harder, faster, and longer, and adjust your diet a bit lower to see more change. Go slow, be patient. If you enjoy cycling, then you are replacing sedentary time with exercise you like that makes you healthier, what's not to like about that!!