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Grapefruit, often confused with pomelos, is a refreshing and flavorful citrus fruit with a unique bitter taste. This tropical citrus fruit is packed with nutrients and health benefits. This fruit is a nutritious addition to any diet, from its high vitamin C content to its abundance of antioxidants. In recent years, grapefruit has gained popularity as a weight loss aid and has been touted for its ability to lower cholesterol levels and improve heart health.

This article will explore how grapefruit may impact blood sugar levels and the health benefits of including this fruit in your diet. 

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Glycemic Index Table

Grapefruit is considered a low glycemic index fruit, with a score of 26, which is lower than oranges (45), strawberries (40), and peaches (28).¹ This low glycemic index rating means consuming grapefruit should not cause dramatic rises or spikes in blood sugar levels.

While fresh fruit is always the best option, many people consume pre-sliced grapefruit that often sits in sugary liquids. Be mindful of these products, as the added sugar will increase the glycemic index of the grapefruit. 

Grapefruit juice is also a popular option, but similar to pre-sliced grapefruit, this beverage choice may contain filler ingredients and added sugars. Review the nutrition label to determine if other ingredients have been added before purchasing these products.

The below glycemic index and glycemic load data is for 100g of raw, pink, and red grapefruit:¹ ²

Glycemic Index


Serving Size


Carbohydrate* per Serving (g)

10.7 g

GL per Serving


Nutritional Facts

Grapefruit is a citrus fruit that is low in calories and high in vitamins, minerals, and antioxidants. Grapefruit contains natural plant compounds called phytochemicals, specifically flavonoids, which studies show can help fight stroke and heart disease.

Grapefruit is an excellent source of vitamin C, providing 64% of the daily value in just half a grapefruit. It is also a good source of vitamin A, fiber, and potassium. Red and pink grapefruit are good sources of beta-carotene and lycopene, which may reduce inflammation and the risk of chronic diseases.

The nutritional information below is for 100g of raw grapefruit.²


42 kcal


10.7 g


0.77 g


1.6 g


0 mg


A (1150 IU), B6 (0.04 mg), C (31.2 mg). Folate (19 µg), Beta Carotene (686 µg), Lycopene (1420 µg)


0 mg

Total Fat

0.14 g

Is Grapefruit Good for Weight Loss?

Grapefruit is a valuable addition to any diet and a must for those looking to lose weight. Grapefruit has several nutritional properties linked to weight loss, specifically fiber content. Fiber promotes fullness and reduces calorie intake.¹⁶ ¹⁷ Also, grapefruit contains few calories and an abundance of water, which will also help you feel fuller for longer.¹⁸

Several studies have found weight loss effects associated with consuming grapefruit. One study found that individuals experienced a reduced waist size when consuming grapefruit daily with meals.¹⁹ However, there were no significant differences between the study participants who drank water, those who ate grapefruit, and those who drank grapefruit juice. This may show that grapefruit, on its own, may not produce weight loss, but adding it to a balanced diet is beneficial.

Is Grapefruit Safe for People Living with Diabetes?

With one of the lowest glycemic index ratings for fruit, grapefruit is a safe choice for people living with diabetes. Eating grapefruit regularly could prevent insulin resistance, a precursor to diabetes.

Eating grapefruit may help control insulin levels, which can reduce the likelihood of becoming insulin resistant.¹⁴ In one study, participants who ate half a raw grapefruit before meals experienced a significant reduction in insulin levels and insulin resistance compared to the control group who did not eat grapefruit.¹⁴ 

Also, eating fruit is generally associated with improved blood sugar control and a reduced risk of type 2 diabetes.¹⁵

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Grapefruit allergies are normally classified as a general fruit allergy or an allergy to citrus fruits. Symptoms of a grapefruit allergy include itchiness of the mouth, lips, or throat, swelling, and redness. In severe cases, allergic reactions can cause hives, difficulty breathing, and anaphylaxis. Please consult a healthcare professional if you suspect an allergy, sensitivity, or intolerance to grapefruit.

Outside of an allergic reaction, grapefruit can interact negatively with certain medications, specifically ones that inhibit cytochrome P450, an enzyme in your body. Eating grapefruit while consuming these medications could cause your body not to metabolize the medication properly, which could lead to an overdose or other health complications.¹³

Medications that typically interact with grapefruit include:¹³

  • Immunosuppressants
  • Benzodiazepines
  • Calcium channel blockers
  • Indinavir
  • Carbamazepine
  • Certain statins

If you are concerned about a grapefruit interaction, please consult your healthcare provider.

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What is Glycemic Index?

The glycemic index (GI) is a measure of how quickly a carbohydrate-containing food raises blood sugar levels compared to a reference food, usually glucose. It ranks foods on a scale from 0 to 100, with higher values indicating a faster rise in blood sugar. The glycemic index (GI) scale is typically categorized as follows: Low GI [55 or less], Medium GI [56-69], High GI [70 or higher]. Foods with a high glycemic index digest rapidly and can cause dramatic fluctuations in blood glucose or glucose spikes.

What is Glycemic Load?

Glycemic load (GL) takes into account both the quality (glycemic index) and quantity (carbohydrate content) of carbohydrates in a specific serving of food. It is a measure of how much a particular food will raise blood sugar levels. GL is calculated by multiplying the glycemic index of a food by its carbohydrate content and dividing it by 100. It provides a more accurate representation of the overall impact of a food on blood sugar compared to the glycemic index alone.

Does Grapefruit Spike Insulin?

Yes, grapefruit can spike insulin levels. Grapefruit contains a compound called naringenin, which can inhibit the enzymes responsible for breaking down certain medications and increase the absorption of some drugs. This can lead to a spike in insulin levels, especially in people with diabetes or insulin resistance. It is important to talk to a healthcare provider before consuming grapefruit or grapefruit juice if you are taking any medications or have a medical condition that affects insulin levels.

Is Grapefruit Low Glycemic?

Grapefruit has a low glycemic index, which means it does not cause a rapid increase in blood sugar levels. This is due to its high fiber and water content, as well as its low sugar content. However, people taking certain medications should consult with their doctor before consuming grapefruit.

Can People Living with Diabetes Eat Grapefruit?

People living with diabetes can eat grapefruit in moderation as it is a low glycemic index fruit. However, grapefruit can interact with certain medications used to treat diabetes, so it is important to consult with a healthcare provider before consuming grapefruit.

Topics discussed in this article:


  1. University of Sydney. (2023, May 1). Glycemic Index – Glycemic Index Research and GI News
  2. USDA FoodData Central. (2019, Apr 1). Food Details - Grapefruit, raw, pink and red, all areas. Retrieved from
  3. Dow, C. A., Going, S. B., Chow, H. H., Patil, B. S., & Thomson, C. A. (2012). The effects of daily consumption of grapefruit on body weight, lipids, and blood pressure in healthy, overweight adults. Metabolism: clinical and experimental, 61(7), 1026–1035.
  4. Rodan A. R. (2017). Potassium: friend or foe?. Pediatric nephrology (Berlin, Germany), 32(7), 1109–1121.
  5. Liu, Z., Ren, Z., Zhang, J., Chuang, C. C., Kandaswamy, E., Zhou, T., & Zuo, L. (2018). Role of ROS and Nutritional Antioxidants in Human Diseases. Frontiers in physiology, 9, 477.
  6. Pawlowska, E., Szczepanska, J., & Blasiak, J. (2019). Pro- and Antioxidant Effects of Vitamin C in Cancer in correspondence to Its Dietary and Pharmacological Concentrations. Oxidative medicine and cellular longevity, 2019, 7286737.
  7. Fiedor, J., & Burda, K. (2014). Potential role of carotenoids as antioxidants in human health and disease. Nutrients, 6(2), 466–488.
  8. Cassileth B. (2010). Lycopene. Oncology (Williston Park, N.Y.), 24(3), 296.
  9. Gajowik, A., & Dobrzyńska, M. M. (2014). Lycopene - antioxidant with radioprotective and anticancer properties. A review. Roczniki Panstwowego Zakladu Higieny, 65(4), 263–271.
  10. Barreca, D., Gattuso, G., Bellocco, E., Calderaro, A., Trombetta, D., Smeriglio, A., Laganà, G., Daglia, M., Meneghini, S., & Nabavi, S. M. (2017). Flavanones: Citrus phytochemical with health-promoting properties. BioFactors (Oxford, England), 43(4), 495–506.
  11. Barghouthy, Y., & Somani, B. K. (2021). Role of Citrus Fruit Juices in Prevention of Kidney Stone Disease (KSD): A Narrative Review. Nutrients, 13(11), 4117.
  12. Gul, Z., & Monga, M. (2014). Medical and dietary therapy for kidney stone prevention. Korean journal of urology, 55(12), 775–779.
  13. Grapefruit and drug interactions. (2012). Prescrire international, 21(133), 294–298.
  14. Fujioka, K., Greenway, F., Sheard, J., & Ying, Y. (2006). The effects of grapefruit on weight and insulin resistance: relationship to the metabolic syndrome. Journal of medicinal food, 9(1), 49–54.
  15. Seino, Y., Iizuka, K., & Suzuki, A. (2021). Eating whole fruit, not drinking fruit juice, may reduce the risk of type 2 diabetes mellitus. Journal of diabetes investigation, 12(10), 1759–1761.
  16. Barber, T. M., Kabisch, S., Pfeiffer, A. F. H., & Weickert, M. O. (2020). The Health Benefits of Dietary Fibre. Nutrients, 12(10), 3209.
  17. Rebello, C. J., O'Neil, C. E., & Greenway, F. L. (2016). Dietary fiber and satiety: the effects of oats on satiety. Nutrition reviews, 74(2), 131–147.
  18. Corney, R. A., Sunderland, C., & James, L. J. (2016). Immediate pre-meal water ingestion decreases voluntary food intake in lean young males. European journal of nutrition, 55(2), 815–819.
  19. Silver, H. J., Dietrich, M. S., & Niswender, K. D. (2011). Effects of grapefruit, grapefruit juice and water preloads on energy balance, weight loss, body composition, and cardiometabolic risk in free-living obese adults. Nutrition & metabolism, 8(1), 8.

About the author

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About the author

Brittany Barry is a national board-certified health coach and NASM-certified personal trainer based in South Carolina.

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Please note: The Signos team is committed to sharing insightful and actionable health articles that are backed by scientific research, supported by expert reviews, and vetted by experienced health editors. The Signos blog is not intended to diagnose, treat, cure or prevent any disease. If you have or suspect you have a medical problem, promptly contact your professional healthcare provider. Read more about our editorial process and content philosophy here.

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