The ketogenic diet has surged in popularity due to its potential to aid weight loss and enhance metabolic health. A cornerstone of this low-carb approach is the careful selection of foods, including fruits. This article explores the compatibility of grapes with the keto diet, while also providing a detailed overview of keto-friendly fruit options.
Understanding the Keto Diet
To fully grasp the importance of fruit selection on a keto diet, it's essential to understand its fundamental principles. The ketogenic diet is characterized by a high intake of fats, a moderate amount of protein, and a very limited consumption of carbohydrates. This macronutrient distribution prompts the body to enter a metabolic state called ketosis. In ketosis, the body shifts its primary fuel source from carbohydrates to fat, burning fat for energy instead.
Many people following keto aim for 20 to 50 grams (g) of net carbohydrates per day. (Net carbs, though not a widely accepted nutrition term, can be calculated by subtracting fiber and sugar alcohols from the total carbohydrates. The idea is to switch your body into ketosis, a state where it burns fat for fuel rather than carbohydrates (its preferred and easy-to-access source of energy). The plan may drastically limit many fruits, whole grains, and some vegetables.
The central nervous system (CNS) cannot use fatty acids as a source of energy since free fatty acids cannot cross the blood-brain barrier (BBB).
Grapes and the Keto Diet: A Problematic Pairing
While fruit offers numerous health benefits, some varieties pose a challenge for those adhering to a keto diet. Grapes, unfortunately, fall into this category. On a keto diet, it's best to limit or avoid grapes due to their high sugar content, which can significantly affect blood sugar levels. Grapes aren’t alone in being problematic for keto dieters. Most wines, made from grapes, contain carbs from natural sugars.
Read also: Diet Plan: No Sugar, Carbs, Dairy
Keto-Friendly Fruits: Delicious and Nutritious Choices
Incorporating keto-friendly fruits into your diet can be a delicious and healthy way to maintain your keto journey. To succeed in a ketogenic diet, pick fruits that are low-carb and don't have a significant impact on blood sugar levels. Fortunately, several fruits can be enjoyed in moderation without disrupting ketosis:
Berries: Berries are an excellent keto option due to their low carbohydrate content. Such yummies provide essential vitamins, fiber, and antioxidants.
- Blackberries: Blackberries have an impressive amount of fiber-nearly eight grams in a cup, per the USDA. Plus, they have a ton of vitamin C: One cup has 30.2 milligrams, which is half of the daily recommended amount. (Step aside, oranges.) They're also known to be one of the richest sources of antioxidants-they can collect chemically generated radicals, potentially preventing many human disorders caused by said radicals, according to research from 2023 in the International Journal of Molecular Sciences. Plus, one cup includes six grams of net carbs, so it's not a bad idea to add these to your morning yogurt.
- Raspberries: Thanks to their fiber and antioxidant content, raspberries have been studied for health benefits including reduced inflammation, per 2024 research in Food Frontiers, and lower risk of type 2 diabetes, according to a 2021 study in the International Journal of Environmental Research and Public Health. One cup of raspberries contains 6.6 grams of net carbs-so toss them in a lunch salad or your morning smoothie.
- Strawberries: A cup of strawberry halves contains a little more than eight grams of net carbs-but you can cut that number in half if you aim to eat a 1/2 cup. These berries offer serious perks: Eating them can reduce insulin resistance-which is when your body doesn’t respond properly to insulin and affects how you process sugar-according to 2020 research in Current Developments in Nutrition. They also may improve vascular health, per a 2021 study in The Journal of Nutrition.
Avocado: Avocado is loved for its super creamy texture and high healthy fat content, which make this fruit both a filling and nutritious keto-friendly choice. Avocados are abundant in monounsaturated fats, fiber, potassium, as well as vitamins C and E. Not only does a cup of sliced avocado contain a glorious 22 grams of heart-healthy fat, but it has less than three (!) grams of net carbs, per the United States Department of Agriculture. Avocado is also associated with better cognitive function, according to 2021 research in Nutrients.
Tomatoes: Tomatoes (yes, it is a fruit!) are ideal for a keto diet in moderation as they are low in carbohydrates. They bring a solid source of Vitamin C, potassium, and the antioxidant lycopene. Tomatoes are great for heart health, as tomato consumption has been linked to preventing and managing hypertension due to the presence of the antioxidant lycopene, according to a 2023 study in the European Journal of Preventive Cardiology. A cup of chopped tomatoes has just a little over five grams of net carbs, making it a great addition to your keto diet, either as a snack or salad topping.
Olives: Olives, whether green or black, are an excellent source of healthy fats and antioxidants with minimal carbohydrates. They are rich in monounsaturated fats as well as vitamin E, which are essential for overall health. One cup of olives pack about 21 grams of fat and less than one net carb, per the USDA. Bonus: Not only are they known for their anti-inflammatory effects, but they're also great for heart health, according to 2020 research in the Journal of Nutritional Science.
Read also: Is the Carnivore Diet Right for You?
Coconut: Coconut is a quite versatile and keto-friendly fruit, available in various forms. Whether you choose coconut oil, coconut milk, or unsweetened shredded coconut, you can benefit from its medium-chain triglycerides (MCTs). A 1/2 cup of shredded coconut meat yields about 13 grams of fat, and a respectable five grams of net carbs. Plus, this fruit is loaded with fiber (one cup of it shredded has 7.2 grams, per the USDA), which is super healthy for your gut. Coconut has also been studied for its MCT (medium chain triglycerides) oil content that may help improve cognitive health, per a 2024 study in Phytochemistry Reviews.
Something to note: Sugar is often added to coconut, so make sure you're buying unsweetened-or buy an entire coconut and scoop the meat out yourself.
Cranberry: "A cup of [whole] cranberries has about eight grams of net carbs, so this tart, colorful berry can be included on a ketogenic diet," says Hultin, adding that they’re high in vitamin C. Plus, the fruit has been associated with improvements in visual memory, per 2022 research in Frontiers Nutrition. Add some to a salad for a beautiful garnish, or blend them into your next keto fat bomb smoothie.
Kiwi: "Kiwis are naturally portioned and a small fruit contains only eight to nine grams of net carbs," says Hultin. They "are rich in potassium and vitamin C, as well as a great source of fiber, so they do complement a ketogenic diet." Kiwis have also been shown to act as a natural laxative to help you poop, adds Kaitlyn Randall, RDN, a registered dietician-nutritionist for WellTheory. "This is especially important when following such a low-carb diet, because constipation can become an issue," she says. Carry one for a snack on the go, or enjoy it as part of a healthy breakfast.
Starfruit: Also called carambola, starfruit delivers about nine grams of carbs and about four grams of fiber per one cup, which amounts to five net carbs, says Bensley. If you've never had starfruit before, its taste leans citrusy-and borderline sour-depending on ripeness. It's also packed with vitamin C, Bensley adds. Like kiwi, it makes a great snack.
Read also: Quick Weight Loss with Cabbage Soup?
Cucumber: Yes, cucumber is actually a fruit-and is a great option for keto followers as it's made up of mostly water and has nine grams of net carbs, per the USDA. What it lacks in carbs, it makes up for in satisfying crunch, especially when seasoned with your favorite salt and herb blends.
Gooseberry: If you're a fan of grapes, which aren't very keto-friendly, you can try satisfying that craving with gooseberries. They're a member of the currant family and are very similar in size, shape, texture, and taste to grapes-but they taste a tad more acidic. Best of all, a whole cup clocks in at 8.5 grams of net carbs, Bensley says.
Eggplant: Another fruit in disguise, eggplant is a super versatile, keto-friendly option that can easily be the main attraction at lunch or dinner. Toss it with some chickpea pasta, or roast it for a salad and sprinkle it with cheese. No matter how you serve it, a cup will set you back just about two net carbs, says Bensley.
Zucchini: It's assumed that squash is a vegetable, but by definition, it's a fruit, because it comes from a flowering plant and contains seeds. That makes zucchini-every low-carb lover's favorite noodle substitution-a contender for this list, sitting at 4 grams of net carbs, per the USDA. Pro tip: "The smaller- to medium-sized zucchinis have the best flavor-not the biggest," she adds.
Pumpkin: Turns out, it's not just for carving in October. One cup of pumpkin has about seven grams of net carbs, per Bensley, and contains 245 percent of the recommended daily intake of vitamin A, "an essential vitamin," she adds. You can roast it and blend it into a creamy soup, or top a salad with it (and its seeds).
Fruits to Avoid or Limit on Keto
Some fruit representatives are better to avoid due to their high sugar and carbohydrate levels. While fruit is normally considered a healthy food, it's also pretty high in carbs due to its high sugar content.
Bananas: With 25g of carbs per 100g serving, bananas are too high in carbs. According to the USDA, one banana has more than 21 g of net carbs, which means you may blow your entire allowance on a single one. “We advise people on a lower-carb diet to avoid bananas, particularly in the beginning and when they’re aiming to lose weight,” says Burnison. If you increase your carb goals once you’ve lost weight and are in maintenance mode, you may opt to eat bananas occasionally while on a keto diet.
Pineapple: Pineapple is a tropical fruit that's popular for its sweet taste. However, it's unsuitable for the keto diet due to its high sugar content.
Mangoes: While mangoes are undoubtedly delicious, they tend to be high in sugar and carbohydrates.
Apples: Apples aren't an ideal option for those on a keto diet as the fruit is high in sugar and carbohydrate content. If you really want an apple, you're better off with a yellow or a green one, which have less sugar.
Dates: Dates are often a staple in healthy diets because they make a sweet snack that is also full of fiber and vitamins. But they're a little too sweet to be keto-friendly.
Certain fresh fruits: Some fruits may be higher in carbs than others, which could keep you from reaching or maintaining ketosis. Here’s the breakdown of some high carb fruits:
Fruit Carbs per Serving Bananas High Grapes High Mangoes High Apples High Pineapple High
Although these can’t be staples in a keto diet due to their high carb content, they still boast an array of nutrients and dietary fiber, which is good for digestion and heart health. As such, you may choose to eat them occasionally, but be mindful of your portion sizes and daily macronutrient targets.
Meal Planning with Keto-Friendly Fruits
Planning meals in advance is a crucial habit for those adhering to the keto diet. It guarantees that you always have healthy and convenient options available.
Here are a few ideas for incorporating keto-friendly fruits into your meal prep:
- Chia Seed Pudding: Instructions: Use your mason jar to mix chia seeds and unsweetened almond milk with your favorite keto-friendly berries.
- Chicken and Avocado Salad: Instructions: Mix diced cooked chicken, mashed avocado, diced tomatoes, as well as chopped olives.
- Coconut Fat Bombs: Instructions: Mix unsweetened shredded coconut with coconut oil and a natural sugar substitute on the like of stevia. Shape the mixture into bite-sized balls, then refrigerate until they reach firmness.
Other Foods to Limit on Keto
Besides high-sugar fruits, several other food groups should be limited or avoided on a ketogenic diet:
- Root Vegetables: Root vegetables are high in fiber and somewhat high in carbs, which goes against the main principle of keto. Starchy vegetables, like potatoes, are a definite "no" for the keto diet - they simply have too many carbs. Sweet potatoes are a starchy veggie, and you should think twice about them now that you’re on keto, says Dr. Herrmann. A medium sweet spud has about 20 g of carbs.
- Legumes: Legumes, which include any kind of bean, lentils, sugar snap peas, and peas, are staples of many healthy eating styles. However, legumes are not so compatible with the keto diet. While legumes are good for you, they're also high in carbs.
- Some legumes and beans may be challenging to incorporate into your keto diet due to their high carb content. Still, they boast dietary fiber, protein, calcium, and other micronutrients. As such, fitting in small portions might be worth the effort.
- Grains and Starches: Grains and starches should also be avoided on the ketogenic diet because of their considerably high carbohydrate content. Grains like quinoa and millet are higher carbohydrate foods and may not fit in a keto diet.
- Eating refined high carb foods may prevent a ketogenic state if you consume more than your daily carb allowance.
- Sweetened Yogurt or Dairy: When adding dairy to your diet, steer clear of flavored or sweetened varieties, which will add to your carb count. This is especially common in flavored yogurt, milk, and cottage cheese. Aim for plain, full fat yogurt or cottage cheese.
- Alcoholic Drinks: Beer, liqueurs, and mixed liquor-based drinks have a high carb and low nutrient count, which makes them foods to limit on a keto diet.
- Juice: Natural fruit juice is high in naturally occurring sugars, and juices with added sugars are even higher in total sugars. Juice also lacks most of the dietary fiber found in whole fruits.
- Sugary Sodas: Sodas are essentially bubbly sugar water that provides zero nutrition and a high carb count.
- Honey and Syrups: Honey and syrups like agave or maple are concentrated sugars, so they can easily increase your daily carb count without otherwise providing significant nutrition.
- Ketchup, Barbecue Sauce, and Other Condiments: Ketchup, barbecue (BBQ) sauce, and sweet chili sauce are a few examples of sugar-packed condiments that don’t provide much in terms of nutrients or fiber.
- Low Fat Diet Foods: Common low fat or fat-free foods that may be high in added sugars include: yogurt, mayonnaise, salad dressings, peanut butter and skim milk. Remember, the keto diet aims to be high in fat to provide your body with energy, so full fat options are the better choice.
- Light or Low Fat Margarine: Although it’s low carb, it’s also low in fat, which is your main fuel source on the keto diet and important for maintaining a ketogenic state.
- Dried Fruit or Trail Mix: When fruit is dried, its sugar is concentrated into smaller serving sizes, increasing the carb content.
General Advice
If you're thinking about embarking on a ketogenic diet, you probably already know you’ll be avoiding processed grains and sugar like pizza and muffins. But many other foods you’ll nix on this extremely low-carb, high-fat diet aren’t necessarily unhealthy. Indeed, many “no” foods are packed with health-promoting vitamins, minerals, and fiber but also have too many carbs for the restrictive keto diet.
Keto isn’t right for everyone. “For some people, the keto diet can be potentially harmful,” says Alyssa Burnison, RD, a regional registered dietitian for the supermarket chain Hy-Vee in Sioux Falls, South Dakota. That includes people who take insulin for type 2 diabetes or type 1 diabetes, she says. If you have any chronic health condition that you’re hoping to treat with a keto diet, talk to your doctor first or work with a registered dietitian; they can best advise if this is a safe diet for you.