Many people think bananas are high in carbohydrates while many important factors for weight loss: low calories and fat but high fibre. Although bananas are little higher in calories and carbohydrates than than some fruits, they are not considered a high-calorie food. A medium banana has around 92 calories, less than many diet snack foods that contain around 100 calories.Bananas also contain very little fat, about 0.5 grammes in one banana, but are are very high in fibre. They are also rich in potassium as well as vitamin A, a wide range of B vitamin, vitamin C, folic acid, magnesium and calcium. So bananas contribute to a healthy and balanced diet whether you are trying to lose weight or not.