Analyze the calories of what you are eating overall, don't kid yourself, do an honest assessment. Riding consumes calories but not a huge amount, depending on your effort it can be from 600 to 1000 cal/hour. If your normal resting daily calorie burn is 2000 cal and you add a two hour ride to that then you may be at 3500 cal for the day. If you want to loose weight then your cal intake should be around 3000 for that day. It takes a 3500 cal deficit to loose one pound and about 1lb/week is a good rate.
What I find with riding it is too easy to come home and have a beer (or 2) and come dinner an extra big helping (or 2) and before long I have put in more calories than the ride took away and I find myself gaining weight - one seasaon a few yeaars back I put on 10 lbs riding
. So I measure helpings and push away from the table - I also limit the beer/wine intake. I typically loose about 0.5 to 1lb/week. Since late April I have droped 10 lbs and am back to the weight I was last Oct. I am shooting for 6 more lbs and thats light enough.