I think the best "diet" is portion control. However, in my honest opinion I don't think any "diet" works long term. I think you have to make a permanent change along with exercise. Anyone can lose weight for a month or two, keeping it off involves making life changes.

If you are willing to do that along with cycling I am sure that you will be succesful. I wish you the best of luck and hope that in the next year you have reached all of your goals.

*btw, this is coming from someone that lost 50 pounds way too fast but made permanent changes and kept it off for over a year now.