I am not a big girl but I have been working at losing fat and gaining muscle and have lost 22 lbs in the past year. During that time I ate between 1200-1500 calories a day. The closer to 1500 I get, the less likely I am to lose. They stress not to go under 1200 because your body thinks you're starving and hangs on to the fat. No idea if this is true or not.

I ride 100-200 km a week, most rides about 1.5 hours long. I do not eat anything on these rides - I just drink water. On 3 hour rides, I will eat one small snack (100-200 calories max). So - there are no "bike calories" for me. Some days, like today, I burn more than I consume - I try not to use that as an excuse to pig out for dinner that day.

If you are bigger than me, you can probably eat more calories than I do and still lose weight. I wouldn't be eating less than 1200 if I were you...