With a creamy texture and sweet flavor, bananas may seem like a fattening food. Bananas, however, are a natural food rich in vitamins, minerals and fiber, and they make a healthy addition to any diet. Eating bananas in moderation will not cause weight gain as long as you keep your overall calorie intake in check.

Density

Compared to many other fruits, bananas have a low water content. For comparison, a medium banana contains 88 grams of water, a medium apple contains 156 grams and a medium orange contains 114 grams. A banana is a little more calorie dense – meaning it has more calories per weight – than these other fruits.

Carbohydrates

Some diets vilify carbohydrates – especially sugar -- claiming they are the cause for weight gain. Bananas are often perceived to be high in carbohydrates and sugar. One medium banana contains 27 grams of carbohydrates with 14 grams of sugar. Compare this to a medium apple, which contains 25 grams of carbohydrates and 19 grams of sugar. The Institute of Medicine recommends you consume between 45 and 65 percent of daily calories from carbohydrates – for a 2,000-calorie diet, this amounts to between 225 and 325 grams of carbohydrates per day. A banana takes up 12 percent of your total carb needs. The sugar in bananas is naturally occurring, not the added type that health organizations such as the American Heart Association suggest you avoid, making bananas a better, nutrient-rich choice over processed foods and foods with added sugar.