Are Bananas Low-carb? 3 Main Reasons to Avoid Them on Keto

We have recently discussed the best fruits for the keto diet. You can eat them in small amounts without worrying that they will interfere with your weight loss and healthy ketosis. What about bananas? Are bananas high in carbs?

Bananas are not keto. They have too many carbs, and most of them are pure fructose. Eating even one small banana will cause an insulin spike and break your ketosis. However, if you really like the taste and flavor of bananas, there are several keto options for you.

How many carbs does a banana have? Can you replace bananas on a keto diet? How will your body benefit from a banana? Let’s figure out all the answers together!

Is Banana Keto?

How many carbs are in bananas? Are bananas keto-friendly? 100 grams of a ripe banana (about one medium-sized fruit) contain:

  • 89 calories
  • 3 grams of protein
  • 1 grams of fat
  • 23 grams of carbohydrates
  • 3 grams of fiber
  • 20 grams of net carbs.

Based on these proportions and 1 banana calories, I can surely say that bananas are not keto. They contain too many carbs, and one medium banana can break your ketosis. There are three reasons why you should avoid bananas on a keto diet:

  • contain too many carbohydrates, most of which are pure fructose
  • provoke bursts of insulin in the blood and stimulate cravings for sweets.
  • interrupt ketosis and are incompatible with the keto diet.

Keto Banana Substitutes

How to replace banana on keto? If you miss the taste of banana bread, then I have great news for you. You have some keto options for adding banana flavor to your diet. First, you can use banana extract, which has a strong banana taste and delicate aroma. At the same time, it is low in carbohydrates and is perfect for healthy smoothies, keto bread, or keto desserts. You can also use banana-flavored sugar-free protein powder for baking and smoothies.

If you want the delicate texture of a banana, try replacing it with an avocado. The pulp of an avocado is very similar to a banana. However, the carbs in avocados are much lower, and they are a great keto option.

Can you eat green bananas? Eating green bananas is another keto option. The fact is that ripe bananas contain 1% fiber, and the rest of the carbohydrates are fructose. At the same time, green bananas contain about 70-80% insoluble fiber and little sugar. This insoluble fiber has many health benefits. Let’s take a closer look at them.

Banana Health Benefits

So, is banana good for you? Bananas are very beneficial for the human body. They quickly remove excess fluid, thereby lowering blood pressure, as well as reducing swelling. These yellow fruits are a real source of vitamins and essential trace elements:

  • B vitamins: B1, B2, and B6
  • vitamins C (one-third of the daily value) and PP
  • iron
  • calcium and potassium
  • fluorine and phosphorus.

Thanks to such a rich set of nutrients, bananas strengthen blood vessels’ walls and have a beneficial effect on the nervous, digestive, and cardiovascular systems. In addition, small amounts of green bananas have several other beneficial effects on your body.

Preserve Beauty and Longevity

The trace mineral silicon in green bananas is essential for strong nails and strong, shiny hair. It takes part in the synthesis of collagen – “the protein of youth.” It affects the elasticity and firmness of our skin and the health of tissues of internal organs. Many people are deficient in silicon, and eating bananas is a delicious and healthy way to replenish it.

Improve Mood

In combination with magnesium, pyridoxine acts as a natural and very mild sedative for our nervous system. Bananas are even sometimes recommended a couple of hours before bedtime for treating insomnia if there are no contraindications. And thanks to the mood-boosting tryptophan, there is a high likelihood of only having pleasant dreams.

Promote Digestion

Bananas, especially unripe ones, contain many pectins, and these substances are essential for healthy intestinal microflora. In addition, these fruits contain fiber necessary for digestion. Studies have shown that bananas in the diet can help normalize bowel movements in people with both constipation and diarrhea.

Bananas have a soothing effect. Therefore they are a real remedy for heartburn. In addition, they are useful for acidic gastritis. Fiber helps flush toxins from the body and promotes normal bowel function.

Reduce the Risk of Heart Attack and Stroke

Eating green bananas regularly reduces the risk of hypertension and stroke. It is largely due to the high content of potassium and magnesium. These trace elements strengthen the heart muscle, normalize the rhythm of the heartbeat and serve as a good prevention of many age-related pathologies. Bananas also contain vitamin C, which reduces the permeability of the walls of blood vessels.

Potassium and magnesium have a positive effect on the state of the cardiovascular system, help nourish and oxygenate brain cells. High potassium levels help regulate heart rate and maintain optimal blood pressure. Iron prevents anemia by increasing the level of hemoglobin in the blood.

Improve Mental Performance

Bananas help to improve memory and stimulate the brain, so they are recommended during mental stress and in case of difficult work. Also, the fruits relieve the symptoms of anxiety, which prevent a person from focusing on the tasks at hand.

B vitamins and tryptophans will help relieve nervous tension, get rid of stress and depressed mood. Magnesium also has a positive effect on the nervous system.

3 Reasons to Avoid Bananas

Despite all the advantages and balanced chemical composition, bananas are contraindicated for some people. It can be attributed to several factors.

High Glycemic Index

Bananas are high in sugar and high in the glycemic index, so they quickly raise insulin levels. As we have already said, diabetics should be extremely careful with such a product.

If you are overweight, bananas can be consumed in small quantities. There will be no trouble from one fruit in the morning, but it is not worth eating too many of them because this is a high-calorie food.

Increased Blood Viscosity

Bananas remove fluid from the body, which leads to an increase in blood viscosity and a decrease in its flow to some parts of the body. Therefore, it is not recommended to eat fruits for venous diseases, a tendency to form blood clots, as well as for ischemic heart disease.

Risk of Gastrointestinal Diseases

Despite the fact that bananas have a positive effect on the work of the digestive tract, in chronic diseases, it is worth giving them up for a while. Also, bananas are not recommended for irritable bowel syndrome, as they can cause bloating.


In summary, I can conclude that banana is not keto-friendly. It is high in carbohydrates and raises blood insulin levels, interrupting ketosis and making you feel hungry. However, you can keep the delicate banana flavor on your keto menu, thanks to some of the low-carb options. And one of them is green bananas, which are low in fructose but have many health benefits.

Keep in mind, though, that green bananas are not on the list of keto fruits, so if you want to eat them, keep track of the amount and don’t make it a habit. Keep your keto diet healthy and delicious!



Ana R. is a certified nutritionist and healthy eating lover. Over the past 10 years, she has used various methods to deal with obesity and eating disorders. Ana shares her experiences to help readers use healthy eating habits for better health and harmony with the body. She is convinced that this can be achieved by understanding how your body functions and responds to different foods.