I love riding my bike so I enjoyed spin class. It's a real kick in the lower body I can tell you that. I'm pretty sure my ass will be hurting tomorrow.
It's really about finding the foods that keep you full. If you're still hungry, load up with green veggies and time your good fats better during the day to keep you satisfied. And as wise Bunny says, it takes a while to figure out what your body needs through trial and error.