Calories in Starfruit: Nutritional facts for Starfruit Types

A 100g serving of raw starfruit contains 31 calories.

One kilogram (1000g) of raw starfruit contains 310 calories.

A small starfruit (70g) contains 22 calories, while a medium starfruit (91g) has 28 calories, and a large starfruit (124g) provides 38 calories.

Starfruit, or carambola, offers several health advantages due to a rich profile of vitamins and plant compounds. The list below details some of these key health advantages.

• Starfruit is an excellent source of Vitamin C. This vitamin is a powerful antioxidant that supports the immune system by enhancing the function of white blood cells and protecting against pathogens. A review by Carr, A. C., & Maggini, S. (2017), "Vitamin C and Immune Function," confirmed that adequate vitamin C intake is essential for a robust immune system.
• Starfruit contains beneficial plant compounds with antioxidant properties. The fruit has flavonoids and other polyphenols that help protect the body's cells from damage caused by free radicals, which can reduce inflammation. A study by Shui, G., & Leong, L. P. (2006), "Residue from star fruit as a valuable source for functional food ingredients and antioxidant nutraceuticals," concluded that starfruit contains a high level of antioxidants.
• Starfruit promotes digestive health. The fruit provides dietary fiber, which adds bulk to stool and helps maintain regular bowel movements, preventing constipation. A study by Anderson, J. W., et al. (2009), "Health benefits of dietary fiber," demonstrated that increased fiber intake improves laxation and supports gut health.
• Starfruit is low in calories and has a high water content. This combination makes the fruit hydrating and suitable for weight management diets by promoting a feeling of fullness without adding excess calories. A review by Slavin, J. L. (2005), "Dietary fiber and body weight," found that dietary fiber intake is inversely associated with body weight.

Starfruit is a nutritious food for many but the fruit poses serious health risks for individuals with kidney disease. The points below detail these potential concerns.

• Starfruit contains a neurotoxin called caramboxin. In individuals with healthy kidneys, this toxin is filtered out and removed from the body without issue. In people with kidney disease or impaired kidney function, the toxin can accumulate in the blood and cross the blood-brain barrier, causing neurological symptoms like confusion, seizures, and in severe cases, death. A report from the National Kidney Foundation, "Star Fruit: A Danger for People with Kidney Disease," warns that patients with any level of kidney disease should avoid starfruit completely.
• Starfruit is very high in oxalates. Oxalates are compounds that can bind with calcium and form crystals, leading to the formation of kidney stones in susceptible individuals. High consumption can also cause acute oxalate nephropathy, a form of sudden kidney damage, even in people with previously healthy kidneys. A study by Chen, C. L., et al. (2001), "Neurotoxicity of star fruit in renal patients," documented cases of both neurotoxicity and nephrotoxicity linked to starfruit consumption. An alternative fruit with low oxalate content is the apple. A daily suggested amount for individuals with healthy kidneys is no more than one medium starfruit (91g).

Yes, for individuals with healthy kidney function, starfruit is a good food choice because the fruit is low in calories and provides beneficial nutrients. For cellular health, starfruit contains a variety of antioxidants, including flavonoids, that help protect the body from oxidative stress and inflammation. A study by Shui, G., & Leong, L. P. (2006), "Residue from star fruit as valuable source for functional food ingredients and antioxidant nutraceuticals," confirmed the high antioxidant capacity of the fruit. Regarding immune health, starfruit is an excellent source of Vitamin C, a nutrient essential for the proper function of the immune system. A review by Carr, A. C., & Maggini, S. (2017), "Vitamin C and Immune Function," detailed the critical role of vitamin C in defending against pathogens. For digestive health, the dietary fiber in starfruit supports regular bowel movements and contributes to a healthy gut environment. A study by Anderson, J. W., et al. (2009), "Health benefits of dietary fiber," demonstrated that adequate fiber intake is crucial for digestive wellness.

Yes, star fruit is dangerous to eat for any person with kidney disease, regardless of the stage or severity. The danger comes from two substances in the fruit. Starfruit contains a neurotoxin called caramboxin. Healthy kidneys filter this toxin out of the blood, but impaired kidneys cannot. The toxin then builds up and can travel to the brain, causing severe neurological symptoms including confusion, seizures, and coma. A study by Garcia-Cairasco, N., et al. (2013), "Star-fruit-induced neurotoxicity," identified and characterized this neurotoxin. The fruit is also extremely high in oxalates, which can cause kidney stones or lead to sudden kidney failure, a condition known as acute oxalate nephropathy. Research by Chen, C. L., et al. (2001), "Neurotoxicity of star fruit in renal patients," documented this kidney damage. The National Kidney Foundation explicitly warns all kidney patients to avoid starfruit in all forms, including the juice. For people with no history of kidney problems, the fruit is safe to eat in moderation.

The calorie content of starfruit does not change between the different types. Both the tart and sweet varieties of raw starfruit contain 31 calories per 100g serving. The primary distinction between the types is the balance of sugar and acid, which affects the taste but not the overall calorie count in a meaningful way. The lowest and highest calorie counts for raw starfruit are therefore the same. Any change in calories would come from preparation methods, such as adding sugar to make a juice or a dessert.

To eat a star fruit, first select a ripe one that is firm, bright yellow, and has only a little browning on the tips of the ridges. Wash the fruit thoroughly under cool running water. Place the starfruit on a cutting board. There is no need to peel the fruit, as the waxy skin is edible. Trim off the green or brown tips at the end of each of the five ridges. Slice the fruit crosswise to the desired thickness. The slices will have a distinctive star shape. Use a knife tip to remove the small, edible seeds from the center of each slice before eating.

The origin of the starfruit, or carambola, is believed to be in Sri Lanka and the Moluccas, an island group in Indonesia. The fruit has been cultivated throughout Southeast Asia and India for centuries. The fruit's name, carambola, is derived from a Sanskrit word. Starfruit cultivation spread to other tropical and subtropical regions of the world, including the Caribbean, Central and South America, and Florida in the United States. In many Southeast Asian cuisines, the tart varieties of starfruit are used in cooking similarly to a sour vegetable, adding acidity to curries and stews. The sweet varieties are more often eaten fresh or juiced. The use of the fruit as a decorative garnish in Western dishes is a more recent development, capitalizing on the unique star shape of the fruit's cross-section.