http://www.webmd.com/diet/features/glycemic-index-diet

An educated guide in choosing the right foods (sometimes we choose foods that we think are healthy, but may be high on the glycemic index scale). Mangos, for instance, are fruits—so they are good for us, right? Well…tasty as they may be, they are incredibly high on the GI chart and contain some of the most concentrated amounts of sugars of any fruit. Stick with berries for a better fruit choice.