Last week, a reader asked why I included bananas in my list of good carbs for the Adrenal Reset Diet. Her confusion is understandable, since some experts claim bananas are fattening or unhealthy.

Recently, I read one such claim:

“I tell my clients to stick to fruits that either have edible skin, edible seeds, or citrus—bananas do not have edible skin, nor do they have edible seeds really, nor are they citrus. Most of the fiber and nutrients that are in a fruit are in a fruit’s skin. A banana is just the densest piece of fruit that you can put in your body, and since it doesn’t have much fiber, it won’t keep you full.”[1]

Are bananas fattening?

Those who claim they are, argue that bananas cause the body to make lots of insulin, and insulin causes fat growth.

How much insulin we produce is related to how fast a food becomes sugar in our bloodstream. How can you know if a food makes a lot of sugar quickly? The glycemic index (GI) rating tells us. Foods with GI scores above 75 are considered high-GI foods. Bananas have a GI of 62, which is considered low. [2]

Weight loss can be a struggle for anyone, but it is especially hard for diabetics. A study looked at how the starch from unripe bananas affected the weight of a group of obese diabetics. After four weeks of a diet high in bananas, diabetics lost significantly more weight than on a control diet. They also saw improvements in insulin sensitivity from the banana diet. [3]

Bananas are a rich source of resistant fiber, which has been shown to help weight loss. Bananas that still have some green on the skin are even higher in resistant fiber.

Are bananas unhealthy?

No. On the contrary, bananas have been shown to cut risks of stroke, diabetes and cancers.

Stroke risk:
A group of over 90,000 women, ages 50-79, was tracked for 11 years to see how their diets predicted their stroke risk. Those who had the potassium from an extra banana each day had a 25% reduction in their risk of stroke. [4]

Diabetes risk:
Along with helping diabetics lose weight, bananas lower the risk of developing diabetes. [5]

Cancer risk:
Bananas are the most powerful fruit for cutting the risk of kidney cancer. In a large study, 61,000 adult women were asked about their diets and monitored for kidney cancer for 13.4 years.[6] Many types of produce were helpful, but bananas were the best fruit for lowering the risk of kidney cancer.

Are banana skins and seeds inedible?

Back to the opening quote, the trainer argues that bananas are bad foods because the skins and seeds are inedible.

The claim that banana seeds are inedible is pretty easy to dismiss. Bananas don’t have seeds. Bananas are sterile clones, grafted from original plants from thousands of years ago. The common variety is called the Cavendish, and because they are identical clones, they’re at risk for plant infections wiping them out completely. This happened to a variety of bananas in the 1950’s.

Skins from ripe bananas are edible cooked or raw. Skins from green bananas are edible when cooked. The skins are an even richer source of antioxidants, potassium, magnesium and resistant fiber.

How can you use banana skins?

My favorite is to take bananas that are just ripe, cut off the stem and the dark tip, cut them in quarters and freeze them with the skin on. I use the frozen sections when making smoothies in a blender. You want to blend thoroughly because the skins are harder than the flesh. The skins have no apparent effect on taste, and give a big boost in nutrients.

Skins from green bananas can be taken and, after removing the stem and dark tip, cut into small strips 2-3 inches long and 1/2 inch wide. These strips can be made into a high-potassium tea or added to a stir fry. I love stir-frying them with onions, bok choy and mushrooms.

When you eat the skins, be sure you are eating organic bananas. The flesh of regular bananas are low in pesticides, but the skins are not.

With all their nutrients and multiple health benefits, enjoy your bananas without fear!

1 Popsugar Fitness, “8 Foods Celebrity Fitness Trainers Won’t Eat,” Women’s Health Magazine, February 19, 2014, accessed July 9, 2015,
2 “Glycemic index and glycemic load for 100+ foods,” Harvard Health Publications, February 3, 2015, accessed July 9, 2015,
3 Ble-Castillo JL, Aparicio-Trápala MA, Francisco-Luria MU, Córdova-Uscanga R, Rodríguez-Hernández A, Méndez JD,Díaz-Zagoya JC, “Effects of native banana starch supplementation on body weight and insulin sensitivity in obese type 2 diabetics,” Int J Environ Res Public Health. 2010 May;7(5):1953-62. Accessed July 9, 2015. doi: 10.3390/ijerph7051953. Epub 2010 Apr.
4 Arjun Seth, Yasmin Mossavar-Rahmani, Victor Kamensky, Brian Silver, Kamakshi Lakshminarayan, Ross Prentice, Linda Van Horn, Sylvia Wassertheil-Smoller, . “Potassium intake and risk of stroke in women with hypertension and nonhypertension in the Women’s Health Initiative,” Stroke 2014 Sep 4; [e-pub ahead of print], Accessed July 9, 2015.
5 Muraki I, Imamura F, Manson JE, Hu FB, Willett WC, van Dam RM, Sun Q, “Fruit consumption and risk of type 2 diabetes: results from three prospective longitudinal cohort studies,” BMJ. 2013 Aug 28;347:f5001. doi: 10.1136/bmj.f5001. Accessed July 9, 2015.
6 Rashidkhani B, Lindblad P, Wolk A, “Fruits, vegetables and risk of renal cell carcinoma: a prospective study of Swedish women,” Int J Cancer. 2005 Jan 20;113(3):451-5. Accessed July 9, 2015.