How Many Calories Does a Whole Grapefruit Have?

Like other fruits, grapefruit is one of the healthiest foods you can eat. Grapefruit benefits for weight loss are largely due to its low number of calories and high nutritional value. Rich in vitamins, minerals, antioxidants and fiber, this fruit can improve your diet and overall health.

Grapefruits are an ideal food to include in your weight loss diet. These citrus fruits are low in calories and fat and have no cholesterol.

The pink variety provides more calories than its white cousin, which is comparable to the calories in an orange. For comparison, the calories in these fruits and others, according to the USDA, are:

• Pink grapefruit — 52 calories or 3 percent of the daily value (DV) per half fruit (3 3/4 inch diameter)
• White grapefruit — 39 calories or 2 percent DV per half fruit (3 3/4 inch diameter)
• Oranges — 43 calories or 2 percent DV per half fruit (3 1/16 inches diameter)
• Banana — 112 calories or 6 percent DV per fruit

The daily value of the listed fruits is based on a 2,000 calorie diet. The 2015-2020 Dietary Guidelines for Americans has determined the number of calories you need each day to stay healthy, depending on your age and sex.

These estimates range from 1,600 to 2,400 calories per day for adult women and 2,000 to 3,000 calories per day for adult men. The low end of the range is recommended for sedentary individuals, while the high end of the range is for active individuals.

Read more: The Effects of Eating Too Much Grapefruit

Grapefruit is an excellent source of vitamin C, a powerful antioxidant that can help regenerate other antioxidants in your body, such as vitamin E, according to the National Institutes of Health (NIH). The vitamin C content doesn't vary significantly between pink and white varieties — 85 percent of the DV compared to 87 percent of the DV per whole fruit, respectively, according to the USDA.

The vitamin C in grapefruits helps your body maintain a healthy immune defense by fighting off harmful free radicals, Free radicals are molecules produced as byproducts of metabolic functions in your body or from exposure to environmental pollutants. The NIH reports that vitamin C may lower the risk of developing certain cancers, cardiovascular disease and other diseases in which oxidative stress plays a causal role.

This nutrient is often associated with the common cold. Eating grapefruits might help alleviate some of the sniffles you could experience. A meta-analysis of nine trials, which was published in BioMed Research International in July 2018, indicates that although vitamin C won't prevent you from catching a cold, it may shorten its severity and duration.

Vitamin C also helps maintain cartilage and bone tissues by synthesizing new proteins for your skin, connective tissue, tendons, cartilage and bones, according to the NIH. If you have a wound, eating grapefruits may supply the extra vitamin C you need for faster healing.

Most calories in grapefruits come from carbohydrates. These nutrients are converted to glucose, which provides the energy needed to support bodily functions and physical activity, according to the Harvard T.H. Chan School of Public Health.

A half-fruit serving of white grapefruit provides 3 percent of the DV, while a half pink grapefruit delivers 4 percent DV for healthy carbs, according to the USDA. The carbohydrate content of grapefruit juice, per 8-ounce glass, is similar to that of a whole grapefruit.

An important component of grapefruit is fiber, which supports digestion. Fiber is the portion of food that your body can't digest properly, so it passes intact through your intestines. It helps prevent constipation and also slows digestion and the rate at which other nutrients are absorbed into the bloodstream, according to the Food and Drug Administration. This can help improve blood sugar levels by preventing rapid rises in blood glucose following a meal.

A half pink grapefruit provides about 8 percent of the DV for fiber, while a half white grapefruit will deliver 5 percent of the DV. A glass of grapefruit juice has significantly less fiber, so the sugar goes straight to your bloodstream.

The soluble fiber in grapefruit may help reduce total blood cholesterol by lowering LDL ("bad") cholesterol levels. The Mayo Clinic suggests that high-fiber foods may also have other benefits for heart health, such as reducing blood pressure and inflammation. Additionally, high-fiber diets may help protect against diverticular disease and colorectal cancer.

Grapefruits also offer many vitamins and minerals that are essential to maintaining your health. Some of their most beneficial nutrients include:

• Calcium
• Iron
• Potassium
• Magnesium
• Phosphorus
• Copper
• Vitamin A (especially in pink grapefruit)
• B vitamins — thiamine, riboflavin, niacin, B5, B6 and folate

Grapefruit is 88 percent water. This helps keep you hydrated for overall good health without adding calories. Like most fruits, grapefruits are high in sugar, supplying about 8.5 grams per serving, according to the USDA. However, unlike processed foods, fruits contain fiber, which slows sugar absorption into the bloodstream.

An October 2016 study published in Nutrients reported that, despite the high amount of simple sugars in fruit, research has consistently shown that most fruits protect against obesity.

These effects, along with the high levels of vitamins and minerals in fruit, have prompted health organizations to recommend fresh fruit consumption for weight loss. However, researchers warn that fruit juice and dried fruit may contribute to weight gain as they're higher in sugar than whole fresh fruits.

Although fruits and vegetables should make up a large portion of your daily meals, your overall calorie intake from a balanced diet that includes all the food groups is what determines the success of a healthy weight loss plan. Fad diets, including the grapefruit diet that involves a low-calorie intake, are a short-term solution to weight loss. These slimming plans may cause deficiencies in some nutrients and affect your health in the long run.

Read more: 21 Day Grapefruit Diet

At the end of the day, grapefruit isn't a miracle weight loss food. What matters most is your day-to-day commitment to physical exercise and having a diet that allows you to maintain an adequate balance of nutrients, including protein, carbs, fats and vitamins. This is the healthiest and most effective way to lose weight.