Because glucose is the body’s preferred source of energy when cycling, the best food to eat while cycling are foods that are high in carbohydrates and easy to digest.
Sports gels, chews and drinks, honey sticks, bananas, and even jelly beans are all popular, easily digestible choices for topping up your glucose supply during a ride 
. Raisins, chopped dates, and mini-pretzels are also good sources of energy that can be used to refuel during a long ride but should be tested out before race day.
You should begin refueling around 45-60 minutes into a long ride. To maintain adequate energy levels while cycling, you’ll need to consume about 30-60 g/carbohydrate/hour. Many cyclists prefer to split their intake into 20-minute increments to minimize GI discomfort.