Is Grapefruit Keto-Friendly? Carbs in Grapefruit

Is grapefruit keto-friendly? No, grapefruit is not keto; one contains around 21 grams of net carbs, which can trigger blood sugar spikes and push you out of ketosis.

And, what’s more, grapefruits contain compounds that may interfere with the metabolism of certain medications, increasing the risk of side effects and drug toxicity.

Learn about low-carb fruit options that won’t disrupt fat burning.

How many carbs are in grapefruit?

Grapefruit is a popular citrus fruit and an exceptionally rich source of vitamin C. Because of its tangy and slightly bitter flavor, and grapefruit is often believed to be a keto-friendly fruit.

However, this isn’t correct. While pink and red grapefruits have a lower carb count than other citrus fruits, such as oranges and mandarins, they contain too many carbs to be on the keto food list.

Grapefruit nutrition facts

A grapefruit’s exact amount of carbs depends on the variety, size, and ripeness.

According to data published by the U.S. Department of Agriculture (USDA), a medium-sized pink grapefruit (230 grams) typically contains:¹

• 97 calories
• 0 g total fat
• 2 g protein
• 25 g total carbs
  • 4 g fiber
  • 21 g net carbs

Watch the video below to learn why it’s best to avoid eating grapefruit on keto.

Can you eat grapefruit on keto?

No, grapefruit isn’t suitable for a low-carb diet.

To maintain ketosis and benefit from the profound metabolic changes triggered by burning fat instead of sugar, it’s important to limit your daily net carb intake to 20 to 50 grams.

Consuming grapefruits can quickly exceed your daily net carb count, which can interfere with ketone production and may inhibit or slow down ketosis.

Can you have grapefruit juice on keto?

Grapefruit juice isn’t a good option if you are trying to limit your carb intake.

Juicing removes grapefruit’s dietary fiber, which concentrates the natural sugar content and explains why one eight-ounce glass (240 milliliters) of freshly squeezed grapefruit juice can contain as much as 25 grams of net carbs.

Grapefruit and medication interactions

“Consuming grapefruit or grapefruit juice can potentially interfere with the metabolism of certain drugs, which increases the risk of side effects and may even cause toxicity,” explains Dr. Berg.

Grapefruits contain furanocoumarins, an organic compound that binds to a group of enzymes known as Cytochrome P450. These enzymes are located in the liver and small intestines and play a vital role in regulating how quickly toxins and drugs can enter the circulation.

When furanocoumarins bind to Cytochrome P450 enzymes, certain drugs can freely enter the bloodstream in much higher concentrations. This significantly increases the risk of potential side effects and may cause excessive circulating levels of pharmaceutical drugs.

Some common examples of medications affected by grapefruit consumption include:

• Statins
• Antidepressants
• Blood pressure medication
• Anti-anxiety drugs

A study published in the Canadian Medical Association Journal concludes, “One whole grapefruit or 200 milliliter of grapefruit juice is sufficient to cause clinically relevant increased systemic drug concentration and subsequent adverse effects.”²

If you are taking prescription medication and are concerned about potential interactions with grapefruit, it’s crucial to consult with a healthcare provider or pharmacist for specific guidance.

Best fruit to have on a ketogenic diet

Whether a fruit is keto-friendly depends on its carb and fiber content, and understanding how to calculate the net carbs of fruits and berries is crucial for keto success.

Here are low-carb fruit options that are on the Healthy Keto®-approved Food List:

• Blueberries
• Chokeberries
• Blackberries
• Lemon
• Lime
• Raspberries
• Red currant
• Strawberries
• Tart cherries

While berries are naturally high in fiber and low in carbs, it’s important to include them in your net carb count to avoid exceeding your daily carb limit, which can potentially disrupt ketone production and interfere with ketosis.

Three benefits of citrus on keto 

Lemons and limes are excellent keto-approved grapefruit alternatives. Not only do lemons and limes help to satisfy grapefruit cravings, but drinking lemon water has profound health benefits.

Here are three benefits of citrus on keto.

1. Lower risk of kidney stones

Citrus fruits are naturally high in citrate, an organic compound that may help to prevent the formation of kidney stones.

Citrate binds to calcium in the urine, which inhibits the formation of calcium oxalate, the most predominant type of kidney stone.

2. Weight loss

Lemons and limes are rich sources of citrus flavonoids, a group of phytochemicals that promote metabolic health and support weight loss.

A study published in the Journal of Clinical Biochemistry and Nutrition found that citrus flavonoids enhance insulin sensitivity, thereby reducing the risk of insulin resistance, a metabolic imbalance linked to weight gain and difficulty losing weight.³

3. Supports healthy digestion 

Citrus may promote the activity of enzymes involved in the production and release of bile, which plays a crucial role in the breakdown and absorption of dietary fats.

Promoting bile flow aids digestion, enhances the absorption of fat-soluble vitamins, and may prevent bile sludge and gallstones.

FAQ

Sources

1. https://fdc.nal.usda.gov/fdc-app#/food-details/174673/nutrients ?
2. https://pmc.ncbi.nlm.nih.gov/articles/PMC3589309/ ?
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC2581754/ ?