Fruits
Grapefruit
Grapefruit is 91% water, so 100 g (3.5 oz) brings only 32 kcal and 1.1 g of fiber.
Estimated satietyHow it is calculated
Estimated satiety: 5 out of 5
| Starting point | +1 |
|---|---|
| Very low energy density: 32 kcal/100 g | +2 |
| Protein: 2.0 g/100 kcal | 0 |
| Fiber: 3.4 g/100 kcal | +1 |
| Solid food with 90.9 g of water | +1 |
Our own estimate from the values per 100 g: useful for comparing foods with each other, not a measurement in people. Holt index (1995): this food was not measured.
- Prepared by
- Alex Gonzalez
- Last updated
- Next review
- Sources
- 9 primary
- Data
- USDA FDC 173033
No clinical review. No advertising from drug companies and no affiliate links.How we work
Nutrition facts
- Calories
- 38 kcal per serving
- 32 kcal per 100 g (3.5 oz)
- Protein
- 0.8 g per serving
- 0.6 g per 100 g (3.5 oz)
- Carbohydrates
- 9.7 g per serving
- 8.1 g per 100 g (3.5 oz)
- of which sugars
- 8.4 g per serving
- 7 g per 100 g (3.5 oz)
- Fiber
- 1.3 g per serving
- 1.1 g per 100 g (3.5 oz)
- Fat
- 0.1 g per serving
- 0.1 g per 100 g (3.5 oz)
- of which saturated
- 0 g per serving
- 0 g per 100 g (3.5 oz)
- Water
- 109.1 g per serving
- 90.9 g per 100 g (3.5 oz)
Source: USDA FoodData Central: Grapefruit, raw, pink and red and white, all areas (FDC ID 173033), accessed September 23, 2026.
A typical 120 g (4 oz) serving provides about 38 kcal, 0.8 g of protein, and 1.3 g of fiber.
What it is and how to eat it
Grapefruit (Citrus × paradisi) is a large citrus fruit with white, pink or red flesh and a sour, slightly bitter taste. It is called pomelo in Spain, Argentina, Chile and Uruguay and toronja in Mexico, Colombia, Venezuela and Central America; in some places pomelo also refers to another, even larger citrus fruit, Citrus maxima. This page covers raw grapefruit, with 32 kcal, 6.98 g of sugars and 1.1 g of fiber per 100 g according to USDA.
A 120 g (4.2 oz) serving, a few segments, provides 38 kcal, 8.4 g of sugars, 1.3 g of fiber and 0.8 g of protein: a lot of water for few calories, but without the protein the 2025 nutrition advisory on GLP-1 therapy suggests eating first, so it works well afterward or with a yogurt or some queso fresco. The US National Institutes of Health include citrus among the acidic foods that can make reflux worse, a common side effect of these medications according to the Wegovy label; if you get heartburn, especially in the first few days of treatment or after a dose increase, try half a serving. If you take other medicines, ask your doctor or pharmacist whether you can have grapefruit with them.
What the evidence says
The US FDA warns that grapefruit and grapefruit juice can change how some medicines work, including some cholesterol-lowering statins, such as simvastatin and atorvastatin, and some blood pressure drugs, such as nifedipine, because they block an enzyme in the gut (CYP3A4) and let more of the drug into the blood. It does not affect every drug in those classes, Seville oranges, Citrus maxima and tangelos may have the same effect, and the FDA advises asking a doctor or pharmacist and reading the information that comes with each medicine. The Wegovy and Ozempic labels do not mention grapefruit in their interactions section (section 4.5), which does note that semaglutide delays stomach emptying and may affect the absorption of other medicines taken by mouth. With 34.4 mg of vitamin C per 100 g it exceeds the 24 mg for a "high vitamin C" claim, and the 120 g serving provides 41.3 mg, 52% of the 80 mg reference value, which allows the authorized claim "vitamin C contributes to the normal function of the immune system" (Regulations (EC) No 1924/2006, (EU) No 1169/2011 and (EU) No 432/2012).
Satiety
The 1 to 5 score is our own estimate: it starts at 1 point, adds points for low energy density, for protein and fiber per 100 kcal, and for the water in solid foods, and subtracts points for drinks with calories. It is useful for comparing foods with each other; it is not a measurement in people.
What to keep in mind on a GLP-1 medication
Frequently asked questions about grapefruit
How much protein does a 120 g (4 oz) serving of grapefruit have?
100 g (3.5 oz) of grapefruit has 0.6 g of protein. A typical 120 g (4 oz) serving has about 0.8 g of protein. That is 2 g of protein per 100 kcal.
How many calories are in a 120 g (4 oz) serving of grapefruit?
100 g (3.5 oz) of grapefruit has 32 kcal. A typical 120 g (4 oz) serving has about 38 kcal. That is a very low energy density.
How many grams of fiber are in a 120 g (4 oz) serving of grapefruit?
100 g (3.5 oz) of grapefruit has 1.1 g of fiber. A typical 120 g (4 oz) serving has about 1.3 g of fiber.
How filling is grapefruit?
Very filling for the calories it provides: our estimated satiety score is 5 out of 5. Calculation: 1 (base) + 2 (very low energy density: 32 kcal/100 g) + 0 (protein: 2.0 g/100 kcal) + 1 (fiber: 3.4 g/100 kcal) + 1 (solid food with 90.9 g of water) = 5. It is an estimate based on its composition, not a measurement in people.
Is grapefruit a good choice on a GLP-1 medication?
Based on our tags, this is what matters about grapefruit on a GLP-1 medication. “Low energy density”: plenty of volume for few calories; make sure it does not push protein foods off your plate. “Hydrating”: a lot of water, which contributes to hydration when you eat and drink less. These are general guidelines, not medical advice: everyone tolerates foods differently.
How many grams or ounces are in a serving of grapefruit?
We use 120 g (4 oz) as a typical serving. That amount provides about 38 kcal, 0.8 g of protein, and 1.3 g of fiber. It is a reference for calculations, not a recommendation of how much to eat.
Similar foods
Sources
Sources for the data on this page, with the access date.
- Official databaseU.S. Department of Agriculture, Agricultural Research Service.USDA FoodData Central: Grapefruit, raw, pink and red and white, all areas (FDC ID 173033).accessed .
- Clinical guidelineObesity (Wiley).Mozaffarian D, et al. Nutritional priorities to support GLP-1 therapy for obesity: A joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Obesity. 2025;33(8):1475-1503. doi:10.1002/oby.24336.accessed .
- InstitutionNational Institute of Diabetes and Digestive and Kidney Diseases (NIH).Eating, Diet, & Nutrition for GER & GERD.accessed .
- Drug labelEuropean Medicines Agency.Wegovy (semaglutide): EU Summary of Product Characteristics, sections 4.5 (interactions) and 4.8 (undesirable effects), current version.accessed .
- RegulatorU.S. Food and Drug Administration.Grapefruit Juice and Some Drugs Don't Mix.accessed .
- Drug labelEuropean Medicines Agency.Ozempic (semaglutide): EU Summary of Product Characteristics, section 4.5 (interactions), current version.accessed .
- RegulatorOfficial Journal of the European Union (EUR-Lex).Regulation (EC) No 1924/2006 on nutrition and health claims made on foods (Annex).accessed .
- RegulatorOfficial Journal of the European Union (EUR-Lex).Regulation (EU) No 1169/2011 on the provision of food information to consumers (Annex XIII, nutrient reference values).accessed .
- RegulatorOfficial Journal of the European Union (EUR-Lex).Commission Regulation (EU) No 432/2012 establishing a list of permitted health claims made on foods.accessed .