Can You Eat Fruit on Keto?

Fruits are considered healthy due to their high concentrations of micronutrients which are vital to health and wellbeing.

9-Oct 2022, by Lee Sandwith

Eating Fruit on Keto

Fruits are considered a true health food in mainstream nutrition, but they’re pretty much well recognised as not being keto friendly.

In this article I share some context as to why you might wish to include fruits in your keto diet, and which ones are best suited for keto.

Why Eat Fruit in the First Place?

Fruits are considered desirable due to their high concentrations of micronutrients which are vital to healthy development, disease prevention, and wellbeing.

Micronutrients are required in small amounts and are usually measured in milligrams (mg) or micrograms (g).

They fall into two broad categories: vitamins and minerals.

Vitamins are organic compounds which mainly need to come from food as the body either does not produce them or produces very little.

There are currently 13 recognised vitamins which are categorised into either fat-soluble or water-soluble vitamins.

Minerals are inorganic compounds which cannot be synthesised by the human body, thus must be obtained through diet.

Like vitamins, minerals can also be defined into sub-categories.

The major minerals (macrominerals) are those needed in larger amounts, whereas trace minerals (microminerals) are needed in much smaller amounts.

Examples of minerals are magnesium, phosphorus and zinc.

Vitamins and Minerals in Fruit

Fruits are widely thought to be packed with vitamins and minerals, but they are only really a great source of Vitamin C.

Vitamin C is a water-soluble vitamin, also known as ascorbic acid.

Unlike most animals, humans cannot synthesize vitamin C endogenously (internally), so it’s essential to get Vitamin C through the diet1.

Vitamin C is famously thought to protective against the common cold, but technically it plays a role in general immune function2.

It also plays several additional important roles in the body including:

  • Growth, development and repair3
  • Normal metabolic function4
  • Protein metabolism4
  • Reduced risk of chronic diseases such as cancer, cardiovascular disease, and cataract, probably through antioxidant mechanisms4
  • Involved in the biosynthesis of collagen, carnitine, and neurotransmitters5,6

Recommended Amounts

RDA: The recommended dietary allowance (RDA) for adults is 90 mg daily for men and 75 mg for women. Smoking can deplete vitamin C levels in the body, so an additional 35 mg beyond the RDA is suggested for smokers7.

UL:  The Tolerable Upper Intake Level (UL) is the maximum daily intake unlikely to cause harmful effects on health. For vitamin C, the UL is 2000 mg daily. Intake beyond this amount may promote gastrointestinal distress and diarrhea7.

Vitamin C Deficiency

Vitamin C deficiency can lead to Scurvy which causes causes bruising, gum and dental problems, dry hair and skin, and anemia.

Although rare in developed countries, the risk of Vitamin C deficiency is high when the diet provides less than 10 mg daily7.

Despite the RDA, research has shown that 60 mg per day is sufficient to prevent the development of scurvy for one month8.

Given that most people following a keto diet avoid fruit, this is clearly an important topic.

Vitamin C on Keto, Fruits Ranked

Obviously you can supplement with vitamin C, but if you’re like me and prefer to get all of your nutrition requirements from real food.

Fortunately, there are some fruits which you can safely add to your keto diet.

I’ve ranked some of the most common fruits based on net carbs.

All are per 100g unless it made more sense to use a different serving (e.g. one banana).

I’ve also added the vitamin C content and percent RDA (at a 90mg target) per serving for your reference.

Ranking table

Fruit Serving Calories (kcal) Net carbs (g) % RDA
Avocados 90g (1/2 avocado) 144 1.6 11%
Blackberries 100g 43 4.3 23%
Olives 100g 116 4.4 1%
Raspberries 100g 52 5.4 29%
Strawberries 100g 32 5.7 65%
Lemons 100g 29 6.5 59%
Plums 66g (1 medium) 30 6.6 11%
Grapefruit 100g 32 7.0 38%
Watermelon 100g 30 7.2 9%
Cantaloupe 100g 34 7.3 41%
Limes 100g 30 7.7 32%
Honeydew Melon 100g 36 8.3 20%
Cranberries 100g 46 8.4 16%
Guavas 100g 68 8.9 254%
Pink Grapefruit 100g 42 9.1 35%
Apricots 100g 48 9.1 11%
Papaya 100g 43 9.1 68%
Kumquats 100g 71 9.4 49%
Tangerines 88g (1 medium) 47 10.2 30%
Kiwifruit 100g 61 11.7 103%
Pineapple 100g 50 11.7 53%
Blueberries 100g 57 12.1 11%
Oranges 131g (1 medium) 62 12.2 59%
Mangos 100g 60 13.4 40%
Cherries 100g 63 13.9 8%
Pomegranates 100g 83 14.7 11%
Grapes 100g 67 16.3 4%
Apples 182g (1 medium) 95 20.8 5%
Pears 178g (1 medium) 101 21.6 5%
Jackfruit 100g 95 21.8 15%
Durian 100g 147 23.3 22%
Bananas 118g (1 medium) 105 23.9 10%

Best Fruits for Keto

In terms of the best fruits for vitamin C, those with the best net carbs to vitamin C ratio are Guavas, Strawberries, Lemons & Kiwifruit.

If you’re just craving fruits, your best options for keto per serving are Blackberries, Raspberries and Strawberries.

People often recommend Blueberries too, but they have around 12g net carbs per 100g so may be slightly high.

As with all foods though, the dose is the poison so realistically, if you’re smart and plan well, you could include pretty much any fruits in your diet, especially if you’re keto adapted.

Other Notable Nutrient Benefits

As previously stated, vitamin C is the main nutrient contained within fruit; although, as shown in the table, some are relatively low, and you’d need several servings to reach your RDA.

There are some notable exceptions to this though, such as:

Fruit

Nutrient

% RDA per serving

Avocado

Potassium

10%

Durian & Jackfruit

Potassium

9%

Banana

Potassium

8%

Cantaloupe

Vitamin D

20%

Olives

Iron

30%

Vegetables Vitamin C

Many vegetables also contain high amounts of vitamin C, but I’ll cover this in a different article.

The best sources are Bell peppers, Broccoli, Tomatoes and Kale.

Animal Sources of Vitamin C

In the keto and carnivore world, you might often hear that organ meats are the most nutritious foods on the planet.

Whilst this is true for a lot of nutrients, such as vitamin B12, vitamin A and vitamin B3 (Niacin), organ meats are relatively low in vitamin C.

Here’s a list of animal-based vitamin C sources from Dr. Kiltz:

Food Amount Vitamin C %RDA
Salmon Roe (100g) 16 mg 18%
Beef Pancreas (100g) 13.7 mg 15%
Beef Brain (100g) 10.7 mg 12%
Beef Kidney (100g) 9.4 mg 10%
Oysters (6 or 88 grams) 3.3 mg 4%
Grass-fed beef muscle meat (100g) 2.56 mg 3%
Grain-fed beef muscle meat (100g) 1.6 mg 2%
Raw Liver (100g) 1.3 mg 1%

 

As you can see from the table, you could probably get around half of your vitamin C RDA from Salmon Roe, but you’d need to consumer around 250g.

References

  1. Li Y, Schellhorn HE. New developments and novel therapeutic perspectives for vitamin C. J Nutr. 2007;137(10):2171-2184. PMID: 17884994.
  2. Jacob RA, Sotoudeh G. Vitamin C function and status in chronic disease. Nutr Clin Care. 2002;5(2):66-74. PMID: 12134712.
  3. Gordon DS, Rudinsky AJ, Guillaumin J, Parker VJ, Creighton KJ. Vitamin C in Health and Disease: A Companion Animal Focus. Top Companion Anim Med. 2020;39:100432. PMID: 32482285.
  4. Carr AC, Frei B. Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans. Am J Clin Nutr. 1999;69(6):1086-1107. PMID: 10357726.
  5. Burri BJ, Jacob Human metabolism and the requirement for vitamin C. In: Packer L, Fuchs J, eds. Vitamin C in health and disease. New York: Marcel Dekker Inc, 1997: 341-66.
  6. Packer, L. (1997). Vitamin C in health and disease(Vol. 4). CRC Press.
  7. Institute of Medicine (US) Panel on Dietary Antioxidants and Related Compounds. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington (DC): National Academies Press (US); 2000.
  8. Young VR. Evidence for a recommended dietary allowance for vitamin C from pharmacokinetics: a comment and analysis. Proc Natl Acad Sci U S A. 1996;93(25):14344-14348. PMID: 8962053.

About the Author

Lee Sandwith holds a Masters Degree in Clinical Nutrition and is a registered nutritionist with the Association for Nutrition. You can book a free 30 minute consultation with Lee here.

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