Nowadays, sugar is a bad word on the diet, but bananas aren't so bad. In addition to reducing your intake of added sugars, bananas also contain a healthy dose of fiber, which is pumped into foods where it doesn't exist naturally. The sugar in bananas is natural and comes with a good dose of fiber.
When you need to stay energized, bananas are a good mid-day snack or addition to your meals because fiber slows digestion (sugar and carbs otherwise burn quickly).