Can you clarify these cycling questions please?

it better to roll out of bed in the morning and jump straight into the saddle for 25 klms on a fat wheeled mountain bike or is it better to have breakfast first? Is it better to ride EVERY DAY if you can stand the initial pain or is it better to rest at times? Is 25 klms daily going to be much help to losing a belly given that the 25 klms is ridden hard and with hills or is more required? Is a racing hybrid bike with thinner tyres a better proposition for weight loss than a mountain bike given that you can ride further, easier on a racing hybrid.