Fruits are often not low enough in carbs for ketogenic diets. Discover whether grapefruit is a keto-friendly exception and a few substitutes.
Raw grapefruit contains around 9.1 grams of net carbs, which means total carbohydrates minus fiber, per 100 grams.
Since this is somewhat high compared to what most people can deal with on ketogenic diets, it is fair to say that grapefruit is typically not that keto-friendly.
At the same time, it is worth noting that you may still be able to consume small amounts while staying in ketosis. If you really like grapefruit, this could be worth considering.
If you don’t necessarily like grapefruit but just want something with a sweeter taste, choosing one of the lower-carb fruits will make it easier to stay in ketosis.
Total and net carbs in grapefruit
By looking at the total and net carbs in grapefruit you can figure out whether this fruit is keto-friendly in your situation and how much you can eat.
100 grams of grapefruit contain the following amounts of carbs (1):
- Total carbs: 10.7 grams
- Of which fiber: 1.6 grams
- Net carbs: 9.1 grams
Adding 9.1 grams of net carbohydrates on top of the other foods in your diet will often kick you out of ketosis.
In turn, you can say that grapefruit is generally not that keto-friendly.
One cup of grapefruit is about 180 grams and contains the following amounts of carbs:
- Total carbs: 19.3 grams
- Of which fiber: 2.9 grams
- Net carbs: 16.4 grams
As you can expect, eating bigger amounts of grapefruit will also mean you are consuming more carbohydrates.
It will be very hard to fit the 16.4 grams of net carbs in one cup of grapefruit into a keto-friendly diet.
On the flip side, you can also consider consuming smaller portions of this fruit. This would make it easier to stay in ketosis.
Other nutrition information grapefruit
How many carbohydrates grapefruit contains is definitely important on a ketogenic diet but it can be worth checking the other nutrients too.
Sometimes it is worth adding small amounts of foods that are somewhat higher in carbs to your keto diet to get the valuable fats, proteins, vitamins, and minerals in it.
100 grams of raw grapefruit contain the following nutrients (1):
- Calories: 42
- Protein: 0.8 grams
- Carbs: 10.7 grams
- Part of the carbs that is fiber: 1.6 grams
- Fat: 0.1 grams
- Vitamin C: 52% of the DV (Daily Value)
- Vitamin A: 23% of the DV
- Potassium: 4% of the DV
- Thiamin: 3% of the DV
- Vitamin B6: 3% of the DV
And some other vitamins and minerals in smaller amounts.
The extra nutrients in grapefruit are welcome but at the same time, they are not that impressive either. You can like find foods lower in carbs but higher in these nutrients.
From a nutrition standpoint, squeezing grapefruit into your keto diet is likely not worth the effort.
Carbs in grapefruit juice
You can also remove the juice from grapefruit and drink this on its own.
However, removing the fiber does influence the nutrition details per 100 grams and in turn, how keto-friendly this food/drink is a lot.
More specifically, you can find the amounts of carbs in raw grapefruit and grapefruit juice in the table below (1, 2).
| Values Per 100g | Raw Grapefruit | Grapefruit Juice |
|---|---|---|
| Total Carbohydrates | 10.7 g | 9.2 g |
| Of Which Fiber | 1.6 g | 0.1 g |
| Net Carbs | 9.1 g | 9.1 g |
Interestingly enough, the nutrition sources imply that raw grapefruit and its juice contain similar amounts of carbs per 100 grams.
That means grapefruit juice is still not keto-friendly. Even less so than the actual fruit because there is less fiber in it (which reduces blood sugar spikes to some extent).
Additionally, it is a lot easier to consume 100 grams of grapefruit juice than the same weight of the whole fruit.
And if these things were not enough to steer you away from grapefruit juice, many brands also add sugar to their drink. This makes the juice even less keto-friendly.
Why grapefruit is sometimes keto-friendly
By now it should be clear that grapefruit is typically not keto-friendly. That being said, there are still situations where you can eat this fruit and stay in ketosis.
To understand why this is and to avoid overdoing it, you can quickly go over the keto fundamentals below.
Ketogenic diets are ways of eating where you keep your carbohydrate intake low enough to stay in ketosis. Ketosis is a state where you mainly burn fat as fuel (3).
How many carbohydrates you can eat on keto actually depends on details like your weight, muscle mass, genes, workout habits, etc. This keto fact makes reality more confusing.
Even so, there are still general macronutrient intake recommendations. These are not perfect for everyone but do give some indication of how many grams of grapefruit would be keto for you.
One of these recommendations is that you want to get 55%-60% of your calories from fat, 30%-35% from protein, and 5%-10% from carbohydrates.
If you apply these numbers to your diet, you will likely get that you can eat about 20 to 50 grams of carbs a day.
Something to note is that you typically don’t include the fiber in grapefruit and other foods in these amounts. It is true that fibers are carbohydrates but your body processes them in more keto-friendly ways.
How to avoid eating too much grapefruit on keto
The keto fundamentals above mean that you will only be able to consume small amounts of grapefruit if you want to stay in ketosis.
Slicing up a few grapefruits and eating unlimited amounts will typically not be a successful ketogenic diet strategy.
Instead, you can reduce the risk of eating too much grapefruit on keto by following some of these tips:
- Figure out beforehand how many grams of grapefruit align with your ketogenic diet goals
- Prepare this much grapefruit and put the rest somewhere out of sight
- Don’t eat unlimited amounts of grapefruit while doing other activities
- If you really like grapefruit and crave it too much you likely want to buy smaller or no portions
Even if you follow these tips, it is possible that you get out of ketosis. If that is the case, you likely need to reduce how much grapefruit you eat.
Substitutes for grapefruit on keto
Grapefruit is not the sweetest fruit but a bit more so than typical keto-friendly foods.
If this is your main goal with this food, you can also consider a few other fruits that are lower in carbs instead of grapefruit.
These definitely do not have the exact same taste as grapefruit but they may satisfy your fruit cravings in a more keto-friendly way anyway.
The amounts of net carbs next to the fruits below are the net carbohydrate values per 100 grams (4, 5, 6, 7, 8, 9):
- Blackberries: 4.9 grams of net carbs
- Raspberries: 5.4 grams of net carbs
- Strawberries: 5.7 grams of net carbs
- Watermelon: 7.1 grams of net carbs
- Cranberries: 7.6 grams of net carbs
- Cantaloupe: 7.9 grams of net carbs
Something important to note is that these grapefruit substitutes still contain carbohydrates. Often in somewhat high amounts too.
That means you may still need to implement some of the portion control tips above to stay in ketosis.
Why do you follow a keto diet?
Grapefruit contains enough carbs to make it so you will often get out of ketosis when eating it. To what extent this is a problem depends on why you follow a ketogenic diet.
For example, grapefruit can be good for weight loss and decent for health. Even if it raises your carbohydrate consumption to a point where you get kicked out of ketosis.
On the flip side, there are people who need/want to stay in ketosis every minute of the day. If you are in this category, you likely want to avoid grapefruit.
Lastly, it is worth noting that grapefruit juice is often not that good for weight loss, health, and ketogenic diets.
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FAQ
Is grapefruit considered a carb?
Most of the calories in grapefruit come from carbohydrates. In turn, you can say that grapefruit is considered to be a carb.
Is grapefruit juice high in carbs?
100 grams of grapefruit juice contain around 9.2 grams of carbohydrates (including 0.1 grams of fiber). While there are worse drinks, it is fair to say that grapefruit juice is relatively high in carbs.
