Unless I want to feel a lack of energy and hunger,I cannot ride 25 miles without eating before and/or during the ride. I have always been skinny with a naturally fast metabolism. I am 5' 8" and weigh about 150 to 155 with nothing on. In the winter I usually hover within 2 lbs. of 160. Food definitely not overrated. I drink close to 1 quart of liquids, usually water, per hour while riding.