For me it's all about maintaining. To do that requires practice and a willingness to try new things, and to experiment to find what works for you.
For the sake of both performance and weight loss, I NEED to eat while riding. Not much, but some. 3 or 4 fig newtons per hour is a good fuel for me, personally. Eat before you get hungry, drink before you get thirsty.
Eating a bit while riding helps performance by keeping glycogen up so you can ride harder for longer, and for me, it's extremely important for weight loss, because if I don't eat while riding, I find myself starving afterwords and I then overeat. Long, slow distance while munching slowly the entire way has been one of my keys for weight loss, it keeps the hunger away after rides so I'm not tempted to eat too much and cancel out all the hard work I did on the bike.
It doesn't take much, and experiment to find something that is easy for your body to digest quickly. It doesn't do you any good if the food is just sitting in your stomach waiting to be digested.