A red ruby grapefruit is a healthy and nutritious fruit that is low in calories and high in vitamins and antioxidants. With its sweet-tart flavor and vibrant pink flesh, grapefruit is a citrus fruit that can be enjoyed as part of a balanced diet. Determining the calorie content of a grapefruit can help with meal planning and calculating daily calorie needs.
Quick Answers
– A medium-sized red ruby grapefruit (approx. 4 inches diameter) contains about 92 calories.
– The calorie content comes mostly from natural sugars (mainly fructose) in grapefruit.
– Grapefruits are low in calories compared to other fruits. There are more calories in a banana, apple, or orange of equal size.
– Grapefruits get their pink/red color from lycopene, which acts as an antioxidant in the body.
Calculating Calories in Grapefruit
The calorie content of a grapefruit depends on its size. Larger grapefruits will have more calories and smaller ones will have fewer. On average:
– A small grapefruit (3 inch diameter) has around 64 calories
– A medium grapefruit (4 inch diameter) has around 92 calories
– A large grapefruit (5 inch diameter) has around 120 calories
Here is a more detailed calorie breakdown for different sizes of red ruby grapefruit:
| Grapefruit Size | Weight | Calories |
| Small (3″ diameter) | approx. 200g | 64 calories |
| Medium (4″ diameter) | approx. 300g | 92 calories |
| Large (5″ diameter) | approx. 400g | 120 calories |
As you can see from the table, a medium 4-inch red ruby grapefruit of around 300 grams contains about 92 calories.
This calorie number is based on the standard food energy density for grapefruit, which is approximately 0.3 calories per gram. So a 300 gram grapefruit would contain 300 x 0.3 = 92 calories.
Grapefruit Calories Compared to Other Fruits
Grapefruits are relatively low in calories compared to many other popular fruits. Here is how they compare per 100 gram serving:
– Grapefruit: approx. 42 calories
– Banana: approx. 89 calories
– Apple: approx. 52 calories
– Orange: approx. 47 calories
– Grapes: approx. 67 calories
– Peach: approx. 39 calories
– Pear: approx. 57 calories
– Strawberries: approx. 32 calories
– Blueberries: approx. 57 calories
As you can see, even though grapefruit has more calories than berries, on average it contains fewer calories than bananas, apples, grapes, pears and some other fruits.
So grapefruits can be a more calorie-conscious choice for a fruit serving.
Nutritional Benefits
One reason grapefruits are healthy despite their natural sugar content is that they provide a range of vitamins, minerals and plant compounds. Some of the key nutrients in a red ruby grapefruit include:
– Vitamin C – A medium grapefruit contains about 70 mg of vitamin C, which is 78% of the recommended daily intake. Vitamin C acts as an antioxidant and helps support the immune system.
– Vitamin A – Grapefruits contain beta-carotene, which the body converts into vitamin A. One medium grapefruit provides about 28% of the RDI for vitamin A.
– Lycopene – The red/pink color of ruby grapefruit comes from lycopene. This antioxidant has been linked to lower risk of some cancers.
– Potassium – With 196 mg per medium grapefruit, they can help increase potassium levels which support heart health and normal blood pressure.
– Thiamine – Grapefruit contain some thiamine (vitamin B1), which supports carbohydrate metabolism and nerve function.
So the vitamins, minerals and antioxidants in grapefruit provide a range of health benefits that make up for their natural sugar content.
grapefruit Calories from Sugar
Despite being relatively low in calories, almost all the calories in a grapefruit come from sugars.
The two main sugars in grapefruit are:
– Fructose – This simple sugar makes up about 59% of the carbs in grapefruit. It is sweeter than regular sugar.
– Sucrose – Grapefruit contains some sucrose, which is a disaccharide made from glucose and fructose bonded together.
There are about 9 grams of sugar total in half a medium red ruby grapefruit. So in a 92 calorie grapefruit, approximately 83 of those calories come from the 9 grams of sugar.
While grapefruits are high in natural fruit sugar, it is generally considered healthy as part of a balanced diet. The fiber content helps slow absorption of the sugar and prevents an unhealthy spike in blood glucose.
Eating fruit whole provides healthier sources of sugar compared to processed sugars and syrups used in sodas, candies and baked goods.
Ways to Enjoy Grapefruit
Here are some healthy and tasty ways to enjoy grapefruit:
– Eat grapefruit slices raw – Cut a peeled grapefruit into slices or wedges for a quick, easy and healthy snack. Can enjoy on its own or optionally sprinkle a little cinnamon on top.
– Make a grapefruit salad – Combine grapefruit chunks, avocado slices, nuts and a drizzle of olive oil. Can add grilled shrimp or chicken for a protein-packed main meal salad.
– Blend into a smoothie – Combine grapefruit chunks with yogurt or milk of choice, along with other fruit. Spinach or kale can be added for green smoothies.
– Make grapefruit juice – For a refreshing drink, juice grapefruits and serve chilled. Can also combine with orange juice.
– Broil grapefruit halves – For a warm dessert, top halved grapefruits with a little honey and broil until browned.
– Use in salsa – Combine diced grapefruit with red onion, chile pepper and cilantro for a unique salsa pairing for fish or chicken.
– Include in a fruit salad – Mix sections of grapefruit in with other fruits like pineapple, mango, berries, apple, orange and melon.
So in addition to eating grapefruit raw, there are lots of tasty ways to use this healthy, low-calorie fruit in recipes and meals.
Tips for Choosing the Lowest Calorie Grapefruit
All grapefruit varieties have similar calorie density, but here are some tips for selecting individual grapefruits with the fewest calories per fruit:
– Choose small or medium grapefruits which will have fewer calories than large grapefruit.
– Pick grapefruits that feel heavy for their size, which indicates thicker flesh and less water weight.
– Avoid soft grapefruits, which usually have more water weight.
– Select smooth-skinned grapefruits, which tend to have thicker flesh.
– Pick grapefruits with bright, glossy intact skin, which indicates freshness.
– For ruby red grapefruits, choose ones with bright pink insides rather than pale coloring.
Following these tips can help you choose the lowest calorie grapefruits to reduce the calories per serving. But keep in mind all grapefruit varieties tend to be low calorie as part of a healthy diet.
Grapefruit Calories Frequently Asked Questions
Here are answers to some common questions about the calorie content in grapefruits:
Are pink grapefruits lower in calories?
No, pink and red grapefruit varieties do not contain less calories than white or yellow grapefruits. All common grapefruit varieties have very similar calorie density. The color comes from different antioxidant compounds like lycopene, but does not affect calorie content.
Does grapefruit lower cholesterol?
Some studies suggest grapefruit may contribute to lower LDL (bad) cholesterol levels. This is likely related to it decreasing cholesterol absorption during digestion due to the fiber and other compounds. More research is needed to confirm grapefruit’s role in cholesterol reduction.
Are grapefruits high in sugar?
While grapefruits do contain sugar (fructose and sucrose), they are lower in sugar than many other fruits. A medium grapefruit contains just under 10 grams of sugar, which is lower than most apples, bananas, mangos and grapes. Eaten in moderation, the sugar in grapefruit can be part of a normal, healthy diet.
Is grapefruit good for weight loss?
Grapefruit does have a few properties that make it a reasonable choice as part of a weight loss diet. At only around 100 calories per fruit, they are low energy density. They may also help reduce appetite due to their water and fiber content. However, grapefruit does not have any special fat-burning properties, and any weight loss benefits would need to be from reduced calorie intake.
What is the glycemic index of grapefruit?
Grapefruit has a very low glycemic index of only 25. This means it does not cause a rapid rise and fall of blood sugar. The fiber and fructose content of grapefruit contributes to its low GI ranking.
The Bottom Line
A medium sized red ruby grapefruit of around 4 inches diameter provides about 92 calories per fruit. This calorie count is based on the food energy density, with the calories mostly coming from simple sugars like fructose and sucrose.
Grapefruits are relatively low in calories compared to many other fruits. They also provide an array of vitamins, minerals and beneficial plant compounds that provide health benefits.
Enjoying grapefruit as part of a healthy diet can provide good nutrition without significantly increasing calorie intake. When choosing grapefruits, select smaller fruits, and pick ones that feel heavy for their size with bright intact skin.
So be assured that enjoying the sweet-tart flavor of a ruby red grapefruit only adds fewer than 100 calories to your daily diet.
