Bananas are a highly nutritious fruit used to fuel athletes and boost the health of malnourished children. While sometimes criticized for being high in carbohydrates and calories, they also contain protein and healthy fiber, along with a large dose of healthy potassium. Bananas actually make a healthy snack for just about everyone -- from babies to adults.
The number of calories in a banana depends on its size. A small banana measuring 6 to 6 7/8 inches long contains 90 calories, and one that is 7 to 7 7/8 inches long contains110 calories. Large and extra large bananas that range from 8 inches to over 9 inches contain between 121 and 135 calories each.
Protein in food may be complete or incomplete. Complete proteins contain all the amino acids that the body cannot produce on its own. Bananas do contain small amounts of protein, but they are not considered a complete protein. A banana contains between 1.1 gram and 1.66 grams of protein, depending on its size.
Additional Nutritional Considerations
A medium banana provides 34 percent of the recommended dietary allowance of vitamin B-6, 18 percent for vitamin C, 13 percent for potassium and 11 percent for fiber. It also contains about 3 grams of fiber, with a high component of soluble fiber, which helps slow the rise in blood sugar that occurs after a high-carbohydrate meal. It contains about 450 milligrams of potassium, which your body uses to help balance fluids and keep your kidneys functioning well.