Grapefruit is one of those fruit that you either love or you hate. It has an extremely sour, tangy taste that takes some getting used to. There is no doubt, however, that the grapefruit is a nutritional powerhouse with a lot of benefits for the human body. But how does the grapefruit stack up to the keto diet? In this article, we’ll find the definitive answer to that question.

The ketogenic diet is built around a high fat, medium protein and low carbohydrate macronutrient profile. Many people who go on the keto diet do a great job of cutting out sugary carbs from their diet. However, it is easy to overlook the healthy food options that are out there. Citrus fruit is in that category. It contains natural sugars that are known as fructose. If taken in too large a quantity, fructose can boost your blood sugar level to the point that you kick yourself out of ketosis and blow your diet.

The key take-away here is that you cannot just assume that healthy foods like grapefruits are compatible with the ketogenic diet. Eating grapefruit may benefit your overall health, but if it contains too many sugars it doesn’t belong on a keto diet.

Grapefruit Nutrition

grapefruit nutritionWhen you begin to follow the keto diet for weight loss, you need to go beneath the surface of the foods you are eating and check out its nutritional profile with an emphasis on its macronutrient count to make sure it matches up to your diet. Here’s what you need to need to know about the grapefruit:

Grapefruit Macronutrient Profile (Per 100 grams)

  • 42 calories
  • 0.1 grams Fat
  • 11 grams Carbs
  • 0.8 grams Protein

Grapefruit juice has the following macronutrient profile:

  • 97 calories
  • 0.3 grams Fat
  • 25 grams Carbs
  • 1.8 grams Protein

A half of a grapefruit will provide you with:

  • 119% of Recommended Daily Allowance for Vitamin C
  • 35% of Recommended Daily Allowance for Vitamin A
  • 5% of Recommended Daily Allowance for Calcium
  • 55% of Recommended Daily Allowance for Magnesium

Grapefruit has long been known as the fruit of the Gods. It is a round fruit with yellow-orange colored fleshy pulp inside. In different grapefruit varieties, the flesh may be white, pink or red. The sweetness varies with the color. Deeper colored grapefruit pulp is sweeter than lighter pulp. You should also know that the deeper the color of the grapefruit, the richer it is in lycopene. Lycopene is a well established cancer prevention nutrient.

A typical grapefruit weighs between 42 and 100 grams. It is a low calorie fruit that is ideal for a weight loss diet. The grapefruit is also an effective food to help you to curb your hunger pangs. Grapefruits are at their best during the winter months. However, it is one of the most conveniently available fruits that can be easily sourced year round. Whether taken whole or in juice form, the grapefruit provides a whole host of healthy benefits.

grapefruit vitamin mineralsGrapefruit provides an excellent source of the following essential nutrients to supplement your diet:

  •  Vitamin C
  • Potassium
  • Lycopene
  • Fiber
  • Vitamin A
  • Calcium,
  • Magnesium
  • Vitamin B6

Grapefruit seed extract is an extremely potent immune booster. At present, it is considered to be effective in the fight against over 800 viral and bacterial strains, 100 fungi  strains and a growing number of parasites.  Additionally, Grapefruit extract offers natural antioxidant properties, which allow this supplement to kill bacteria in the intestines and reduce the effects of gastrointestinal disorders.

The grapefruit has also been discovered to be very helpful in the treatment of acne and scars. This is largely due to its alkaline boosting properties. Grapefruit seed extract is also beneficial in the treatment of yeast infections as well as other fungal infections such as thrush and athletes foot. Furthermore, this incredible extract has been found to be active against streptococcus, staphylococcus, helicobacter pylori, bacterial infections from salmonella, E. coli, and other viruses.

Grapefruit seed extract consumption has a natural  alkalizing effect on the body. By assisting the body to maintain an ideal pH level of 7, grapefruit also helps to defeat the aging process.

grapefruit seed ketoGrapefruit seed contains vitamin C, E and bioflavonoid. These are antioxidants which help to fight against the free radicals and allow proper metabolism in the body. Grapefruit seed extract can also be of great benefit in managing many diseases conditions such as colds and flu, sore throat, digestive disturbances and candida infection. Grapefruit has also been shown to help treat such conditions as athletes’ foot, ringworm, intestinal amebiasis and giardiasis, herpes, chicken pox and cold sores, ear infection and sinusitis, urinary tract infections, pyorrhea and other gum disorders.

Grapefruit Seed Extract (GSE) is recommended by many health care professionals as an anti-diarrheal for travelers.

Both grapefruit and grapefruit juice have both received the heart health tick from the American Heart Association.

Grapefruit also has a high water count. With the majority of people not getting enough water, this is another advantage of this food.

On the negative side, both grapefruit and grapefruit juice are known to interact with a number of medications. Researchers are not sure, but they believe that the compound within the grapefruit that causes the problem is furanocoumarin. This compound binds itself to an enzyme in your intestines, in a track known as CYP3A4. This reduces the body’s ability to absorb certain medications. As a result the medication will pass directly through the gut and into the bloodstream.

Grapefruit & Weight Loss

grapefruit weightloss ketoGrapefruit has been shown in a large number of studies to promote weight loss. In one 2006 study, a group of volunteers was given half a grapefruit before every meal. A control group did not consume any grapefruit. The results showed that the group who had the grapefruit prior to eating their meals had a weight loss that was twice as much as the control group.

The thing that makes grapefruit such a good weight loss stimulant is the ability that it has to control the release of insulin. By balancing out insulin release, blood sugar levels are stabilized. This helps to control a person’s appetite. In addition to promoting dangerous fluctuations in blood glucose levels, insulin is a fat depositing hormone. Controlling its release will help to avoid the storage of calories as body fat.

Another thing that makes grapefruit so good when it comes to weight loss is that it contains an enzyme called AMPK. This has been shown to boost the metabolism so that you burn more calories all day long. The effect of AMPK is similar to that of working out. The ability of this fruit to promote weight loss has even led to the creation of a grapefruit diet.

Grapefruit has also been shown to be a great aid in controlling blood pressure. This benefit is due to the high amount of potassium contained in grapefruit, which has been shown to negate the bad effects of sodium. One effect of this is the lowering of systolic blood pressure. Research has shown that taking half a grapefruit each day can lower systolic blood pressure by 5 points!

Another ingredient of grapefruit that can help to lower blood pressure is pectin. This a form of fiber that has also been seen to bring down systolic blood pressure, while also helping to alleviate the hardening of the arteries.

As we have already mentioned, grapefruit can interfere with some medications. This is true of blood pressure medications. So, if you are taking any blood pressure medication, then you should not consume grapefruit.

glycemic index of grapefruitThe grapefruit is low on the glycemic index, with a rating of 25. This makes it one of the lowest rated glycemic index fruit. That tends to somewhat mitigate the high carb count of the fruit. In addition, the grapefruit is very low in calories. A very filling grapefruit will only add one hundred calories to your daily nutrition total.

For general health and wellbeing benefits, the recommended daily intake is half a grapefruit each day.

Is Grapefruit Keto Friendly?

There is no doubt that the grapefruit has a whole lot of nutritional benefit. However, when it comes to the ketogenic diet, we must focus on just one thing – it’s macronutrient profile. When you are on the keto diet, you will be following a macro profile that is similar to the following:

  • 70% Fat
  • 25% Protein
  • 5% Carbohydrate

Unfortunately the macronutrient profile for grapefruit doesn’t even come close to this. Here is a reminder of the macro breakdown for a 100 gram portion of this fruit . . .

  • 0.1 grams Fat
  • 11 grams Carbohydrates
  • 0.8 grams Protein

On a percentage basis, that would look something like this . . .

  • 0.001% Fat
  • 92.999% Carbohydrates
  • 7% Protein

That means that the grapefruit is not your friend when you are trying to get and stay in a state of ketosis. When you are on the keto diet, your goal is keep your carbohydrates down to between 20 and 50 grams, depending on what particular form of ketogenic nutrition you are following. So, one piece of this fruit could take up your entire carbohydrate count for the day!

As a general rule, then, you should keep grapefruits out of your keto nutrition plan. However, there may be times on a keto diet when you strategically carb load. This could be after 5 days of going strictly keto or it could be after you have completed a workout. Exercise will use up your glycogen levels and so you need to take in some carbs post workout in order to restore glycogen levels in your muscle cells. At these times, you should consider taking in half a grapefruit in order to benefit from the many positive aspects that we have laid out here.

What fruits can I eat on a keto diet?

Now that we have identified that grapefruit is not a good fit for the keto diet, what about other fruit? Is all fruit on the no-go list? Not necessarily.

It all depends on the carb count of the fruit in question.

Although grapefruit is considered to be exceptionally high in its carb count, many fruit, especially citrus fruit, are relatively low in their carb count. But they also contain many healthy ingredients. These include fiber, which is essential for a healthy digestive system as well as helping with weight loss. Here are the 8 best low carb fruits that you can enjoy on the keto diet . . .


Not only is the avocado one of the best fruits you can eat on the keto diet, it is one of the best nutrition positive foods you can eat on keto full stop! That is because it completely reverses the macro count that you get with a fruits like grapefruit. Half an avocado will provide you with 15 grams of fat and just 2 grams of carbohydrates.

avocadoAvocadoes provide you with a ton of health benefits. They will also deliver mono-unsaturated fats that will easily break down into ketones to promote weight loss. use avocado as a spread, add it to salads or just snack on avocado cubes when you feel a little hungry.

Avocadoes are also rich in phytonutrients, such as lutein, which are very good for your immune system, lowering blood sugar and having an anti-inflammatory effect. In addition, they provide you with more potassium than bananas.


olives on ketoOlives are another keto diet friendly food. You will get 3 grams of fat with 10 olives, for a cost of just 1.5 grams of carbohydrates. You also get a good amount of sodium, which is a definite bonus when you’re on the keto diet. That’s because you will naturally excrete more sodium while on keto.

Olives are very high in dietary antioxidants. They have also been shown to reduce blood pressure by increasing the levels of nitric oxide in the blood. This makes them a powerful food to help combat heart disease. The high levels of Vitamin E in olives also makes them great for brain health and as a defensive against the oxidative stress that is caused by free radical damage.


coconut keto dietYou probably already know that coconuts are a keto favorite. A half cup of shredded meat will provide you with 13 grams of fat and just 2.5 grams of carbohydrates. Just be sure that, when you’re buying it off the shelf, there is no sugar added!

Coconuts are a great source of dietary fiber, in addition to magnesium, Vitamin B6, iron, potassium, zinc, copper and selenium. A large portion of the fatty acids contained in coconuts is lauric acid, which has many benefits for the body. One of them is that is increases the amount of healthy HDL cholesterol.


blackberry fruitBecause they are very low in carbohydrates, berries are a very popular fruit option on the keto diet. Among the most loved are blackberries, not only do they taste great, they also provide you with two grams of fiber and only 1.5 grams of net carbs in a quarter of a cup of blackberries.

Blackberries are very high in Vitamin C, giving you more of it than oranges. In fact, one cup of blackberries with provide half of the recommended daily allowance for Vitamin C. Also high in Vitamin K and manganese, blackberries are an effective fighter against inflammation, and heart disease.


raspberriesRaspberries are another keto diet friendly berry. They have about the same number of carbohydrates as blackberries, with 1.5 grams. One of the great things about the keto diet is that you can use whipped cream to your heart’s delight. That means that you can indulge in berries and whipped cream whenever you get the urge. However, don’t get too carried way with the amount of berries that you put into your mouth – even their small number of carbs can quickly add up!

Raspberries are an especially good way to get antioxidants, including Vitamin C, quercetin and gallic acid. It also contains ellagic acid, which has been shown to be beneficial in the fight against cancer.



Strawberries have slightly more net carbs than blackberries and raspberries, at 2 net grams per quarter cup. Strawberries are rich in manganese, potassium, they are high in fiber and rich in polyphenols.


cherry tomatoYes, tomatoes are a fruit – and they happen to be one that is keto friendly. Half a cup of tomatoes will provide you with just two net grams of carbs. Cherry tomatoes are a great addition to the keto diet and can be used in all sorts of keto friendly recipes. Tomatoes contain a key antioxidant called lycopene, which has been seen to have many health benefits, including improving cardiovascular health.

Tomatoes are also a rich in potassium, folate, Vitamin C and Vitamin K.

lemons keto diet weight loss


Few people enjoy chewing on a lemon, but they do make a good addition to salads, water, or sour tea. Squeeze a wedge of lemon into your water, and you are adding just half gram of carbs to your diet.



Limes are a citrus fruit that is compatible with keto nutrition. They are high in Vitamin C, are an aid to digestion and are able to improve cardiovascular health. Limes also have a good mount of water in them.

bell peppers

Bell Peppers

Bell Peppers are a low calorie, low carb fruit that can be used as either fruit or a vegetable. As well as being high in Vitamin C, they also contain a lot of carotenoids and antioxidants. These will improve your immunity, and boost your vision.

plum keto friendly fruit


Plums contain high levels of Vitamins A, C and K as well as providing high levels of such minerals as potassium, copper and manganese. You will get twice as many polyphenols in plums than in virtually any other fruit out there. Finally, plums are rich in antioxidants to fight inflammation in the body.

What About Citrus Fruits?

carbs value citrus fruitsCitrus fruits will have more carbs in them than other types of fruit, so you need to be careful about your consumption of them on a keto diet. Here is a list of fruits with the number of carbohydrates they contain per 100 grams. If you are on a strict keto diet, then you will probably want to avoid anything that contains more thn 7 grams of carbs per 100 grams of weight.

  • Peaches – 8
  • Oranges – 9
  • Clementine – 10
  • Plum -10
  • Cherries – 10
  • Kiwifruit – 12
  • Apples – 12
  • Pears – 12
  • Mangos – 13
  • Grapes – 16
  • Bananas – 20

Fructose and Keto

The type of sugar that is primarily found in fruit is called fructose. This is one of the three main types of sugar, the other two being glucose and sucrose. Because they contain just one sugar molecule, glucose and fructose are known as simple sugars. Sucrose is a complex sugar, being made up of both glucose and fructose.

Carbohydrates are a fast acting energy provider for the body. However, fructose differs in that it must first be converted into glucose by the liver before it can be used for energy. One of the good things about fructose in terms of weight loss is that it does not raise your insulin levels as much as glucose. However there is a downside to fructose. It is not as filling as either glucose or sucrose and can lead to fat storage. Too much fructose can also lead to . . .

  • Increased LDL cholesterol levels
  • Fat storage in the liver
  • Free radical activity

The fact that the liver has to metabolize fructose makes it especially bad news for people who are on the keto diet. Immediately the liver turns fructose into glucose, it will send it to your muscle cells in order to replenish your glycogen stores. This could be enough to knock you out of keto.

The Bottom Line

Grapefruits contain a lot of health benefits and are high in water content. If you are not on keto, we suggest following the recommended daily intake of half a grapefruit each day. However, because of its relatively high carb count, the grapefruit is a food that should not be eaten when you are on a low carb diet such as keto. However, you can benefit from the health giving ingredients of the grapefruit at times when you cycle out of keto or immediately following a gym workout in order to replenish your muscle cell’s glycogen stores.

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