A Banana is a fruit and not a vegetable, as some tend to believe. It is one of the most commonly consumed fruit all over the world.

It rightly holds this winning position because of its power-packed composition of carbohydrates, calories, and nutrients, which provides the consumer with good energy and nutrition.

Like other fruits and plants, the banana has been given scientific names. The scientific names of most species of this cultivated fruit are Musa acuminata, Musa balbisiana, and Musa-paradisiaca.

This curvy fruit is grown throughout the year and is a native of the tropical countries of South and Southeast Asia. Today, however, bananas are grown and come from throughout the tropics in regions like Africa, Latin America, the Caribbean, and the Pacific.

In the United States, it is grown in warm tropical areas such as Florida and Hawaii. They are also grown in non-tropical areas such as California, Louisiana, Arizona, and Texas.

Nature provides the banana with a biodegradable wrapper, which protects the edible part.

Calories in a Banana: Are they fattening?

The calorie content in a banana varies and depends on its size. Weight-wise, one ounce of banana provides 25 calories.

  • A small banana less than 6 inches contains 72 calories.
  • Medium-sized banana 6 inches to 7 inches contains 105 calories.
  • A Banana which is just over 7 inches long will provide you with 105 calories.
  • Bananas that are just over 8 inches long will provide you with 120 calories.
  • A very large banana over 9 inches long will provide 135 calories

An average woman needs to eat about 2000 calories per day to maintain her weight, whereas an average man needs 2500 calories to stay at his existing weight.

Considering the calorie content of a banana and your daily recommended intake of calories, a banana can hardly be blamed for increasing your weight. As a matter of fact, it is recommended for people who are aiming for weight loss.

Bananas are also a good source of fiber and a high intake of fiber is associated with reduced body weight. Secondly, they are also low in fat content and contain no cholesterol.

Carbohydrates in bananas provide instant energy

More than 90% of the calories in bananas are provided by their carbs – both naturally forming simple sugars (glucose, fructose, and sucrose) and starch. As the banana ripens, the sugar content increases and the starch content decreases.

These simple sugars are easily digested and released into the bloodstream giving a quick boost of long-lasting energy. Research has shown that two ripe bananas provide enough energy for a 90-minute strenuous workout. No wonder then that this fruit is the most popular fruit among athletes.

Green bananas are slower to digest. While the yellow ripened banana is quickly digested and provides energy more quickly, the brown much-ripened ones are more quickly digested and provide a faster release of energy than the yellow variety.

Bananas contain the amino acid tryptophan, which is converted into serotonin. Serotonin is a mood elevator and helps to battle depression.

Bananas are natural antacids, which help to fight heartburn. Eating one at night will help to prevent regurgitation, fight heartburn, and will give you a good night’s sleep.

Japanese scientific research at Tokyo University claims that a fully ripe banana with dark spots on its skin contains TNF (Tumor Necrosis Factor), which helps to prevent and fight cancer. It also helps to boost the white blood cell count in the body and increase your immunity.

The glycemic index of banana

The glycemic index (GI) of the banana increases as it ripens. The Glycemic Index (GI) is a relative ranking of the carbohydrate in foods in relation to how they influence the blood glucose levels.

Carbohydrates that are more slowly digested, absorbed, and metabolized are ranked lower on the glycemic scale. These low GI carbs (55 or less) cause a lower and slower rise in blood glucose and, hence, insulin levels. Carbohydrates that are low on the glycemic index are released slowly and therefore, keep your blood sugar levels stable.

Bananas are low on the glycemic index because they release their energy into the blood slowly. They do not, therefore, cause a spike in your blood glucose levels.

Foods with a GI value of less than 55 are considered low GI foods. According to the International GI Database, a fully ripe banana has a glycemic index of 51. A little under-ripe banana has a GI of 42 and over-ripe ones with brown flecks have a GI of 48. The GI index of the banana, therefore, depends on its ripeness.

Nutrition in Banana

An average size banana (7 to 8 inches long and about 100 mg) provides good all-round nutrition as follows:

Macro Nutrients

  • About 27 g of carbohydrates
  • 1.3 g of proteins
  • 0.4 g of fat
  • Zero cholesterol
  • 3.1 g of fiber – Helps to clear bowels.


  • 0.5 mg of vitamin B-6 – great for the nervous system
  • 0.1 mg vitamin B-2 (riboflavin)
  • Small amounts of vitamin B-9 (folate) – good for body cell repair
  • About 4 % of the RDA for vitamin B-1 (thiamine)
  • 12 mg of vitamin C
  • Traces of fat-soluble vitamins A, E, and K


  • Calcium – 5 mg
  • Copper – 0.078 mg
  • Iron – 0.26 mg
  • Magnesium – 27 mg
  • Manganese – 0.270 mg – helps prevent muscle cramping
  • Phosphorus – 22 mg
  • Selenium- 1.0 µg
  • Zinc – 0.15 mg


  • Potassium – 358 mg. This is about 12% of your daily potassium requirement. Stress reduces your potassium levels and so it will be good to have a banana when you are stressed out, fatigued, and irritable.
  • Sodium – 1 mg

The U.S. Department of Agriculture recommends that men eat no more than two ripe bananas and women restrict their daily banana intake to one and a half only.