I have no idea about calories and suchlike, but if you're hungry - eat! You're asking your body to put out more energy and it needs fuel to do this. As long as you eat healthily, not too large portions, often - and most important, don't go into a bike ride hungry, I think your natural appetite control will take care of it just fine 
If I'm not eating enough I notice that I have trouble sleeping soundly, or wake up starving.
Winter riding is much less about badassery and much more about bundle-uppery. - malkin
1995 Kona Cinder Cone commuterFrankenbike/Selle Italia SLR Lady Gel Flow
2008 white Nakamura Summit Custom mtb/Terry Falcon X
2000 Schwinn Fastback Comp road bike/Specialized Jett