Green banana are the unripe version of yellow banana. While you can eat the yellow banana immediately after peeling, the green banana is best eaten cooked, either boiled or fried. Nutritionally, the green banana is a good source of fiber, vitamins and minerals, and contains a starch that may help control blood sugar, manage weight and lower blood cholesterol levels. Green bananas are also high in vitamin B-6, with a 1-cup boiled serving containing 39 percent of your daily value. Vitamin B-6 plays an important role in more than 100 enzymatic reactions in your body. It is also necessary for the formation of hemoglobin, the protein that carries oxygen in your body. Additionally, vitamin B-6 aids in blood sugar control.