Your body needs energy to function. The food you eat provides that energy in the form of calories, but not all calories are the same. The calories in food come from three main types of nutrients, known as macronutrients, including protein, fat and carbohydrates. Carbohydrates serve as the main source of energy for your body and include three types of molecules; starch, sugar and fiber. One medium banana provides 105 calories and nearly 27 grams of carbs.
No doubt you have heard the hype about low-carb diets that proclaim carbs are bad and lead to weight gain. Some carbs, those that come from highly processed foods like white bread and sugary sodas, do cause weight gain. But carbs from vegetables, whole grains, beans and fruits like bananas provide nutrients your body needs for good health. The Institute of Medicine recommends 45 to 65 percent of your daily calories come from carbohydrates.
A medium banana contains almost 15 grams of sugar, meaning sugar makes up nearly 56 percent of the total amount of carbs. Bananas contain three types of sugar: glucose, fructose and sucrose. Approximately 20 percent, or 3 grams, of the sugar in a banana is sucrose. The remaining 12 grams are half fructose and half glucose. Although the Institute of Medicine recommends that no more than 25 percent of your daily calories come from added sugars, the sugars in bananas are natural sugars that provide other vitamins, minerals and fiber.
Your body needs fiber to keep your digestive tract healthy and prevent constipation. Fiber may also help lower blood cholesterol levels. The Institute of Medicine recommends women under the age of 50 consume 25 grams of fiber per day and those over 50 consume 21 grams per day. However, the average American consumes only 14 grams of fiber per day. One medium banana contributes 3.1 grams of fiber toward your daily intake.
In addition to sugar and carbs, bananas contain a variety of other nutrients. One medium banana contains 6 milligrams of calcium, 32 milligrams of magnesium, 26 milligrams of phosphorus and 422 milligrams of potassium. Bananas also provide vitamins including 10 milligrams of vitamin C, 76 international units of vitamin A and 24 milligrams of folate. The natural sugars, carbs, fiber, minerals and vitamins make bananas a healthy part of a well-balanced diet.
Stephanie Chandler is a freelance writer whose master's degree in biomedical science and over 15 years experience in the scientific and pharmaceutical professions provide her with the knowledge to contribute to health topics. Chandler has been writing for corporations and small businesses since 1991. In addition to writing scientific papers and procedures, her articles are published on Overstock.com and other websites.