Carbs in Sweet Potatoes: Are They Keto?

Sweet Potatoes | Carbs | Keto | Benefits | Conclusion | FAQ

Many keto enthusiasts reach for sweet potatoes after intense workouts or when carb-cycling. They are a lectin-free and healthy source of carbohydrates. Therefore, there is a lot of confusion regarding sweet potatoes in keto communities.

How sweet are these roots? Can you eat sweet potatoes regularly on low-carb diets like keto? Finally, there must be some carbs hiding in them. Read on to find out.

Are Sweet Potatoes Keto?

The sweet potato or Ipomoea batatas belong to the bindweed or morning glory family – Convolvulaceae. Nature

Therefore, strictly speaking, the sweet potato is not a potato. Contrary to popular belief, it does not belong to the botanical nightshade family like the potato.

Nevertheless, both families are widely related, belonging to the order Solanaceae.

The sweet potato is native to South America and was domesticated at least 5000 years ago. Today you can find various sweet potatoes in groceries.

Types of Sweet Potatoes

The root vegetable typically has brown or reddish skin with a starchy interior that is orange. However, varieties exist whose interiors can be white or purple.

White Sweet Potatoes

Although the orange sweet potato is more common, the one with a white interior is the classic sweet potato.

In short, you’ll recognize the white sweet potato by its light brown skin and slightly yellow interior. It is only slightly sweet but still has a creamy texture.

Orange Sweet Potatoes

Orange on its inside and reddish-brownish-orange on its outside – this is the sweet potato as we know it.

Since this sweet potato is colloquially known as yams in the USA, many confusions arise. For this reason, yams are also usually mistranslated into sweet potatoes in many dictionaries.

Furthermore, they are sweeter than the classic white sweet potatoes and are now available in almost every corner of the western world.

Purple Okinawa Sweet Potato

Now we come to the Asian market. While their exterior tends to be white, you can identify Okinawa sweet potatoes with a bright purple inside.

Blackberries, for example, get their purple color from anthocyanins. These are color pigments that are said to have an antioxidant effect.

According to studies, purple sweet potatoes have more powerful and, above all, more stable anthocyanins than berries (Li et al. 2019¹).

Although they have as creamy a texture as orange sweet potatoes, they are even sweeter than this relative.

Japanese Satsumaimo Sweet Potato

The satsumaimo is also called the Japanese sweet potato. Its characteristics are precisely opposite to the purple sweet potato: while the skin is purple, the inside is yellow.

Moreover, what sets this sweet potato apart is its tremendous sweetness. When you caramelize satsumaimo in the oven, it tastes remarkably sweet. At the same time, the inside becomes especially golden when you bake it.

Therefore, many people use them in desserts.

Carbs in Sweet potatoes

While sweet potatoes do not contain much fat or protein, they are over ¾ water. However, the net carbohydrate content determines their suitability for a ketogenic diet.

How Many Carbs Are in Sweet potatoes?

100 grams of sweet potatoes provide the following average nutritional values (*):

• Energy: 90 calories
• Protein: 2.0 grams
• Fat: 0.2 grams
• Carbs: 20.7 grams
• Dietary fiber: 3.3 grams
• Net carbs: 17.4 grams

According to the nutrition values, carbs dominate in sweet potatoes. Moreover, they are almost fat-free.

In short, sweet potatoes are high-carb, low-fat food.

Are Sweet potatoes Keto-Friendly?

Sweet potatoes are not suitable for a ketogenic diet. They have a fat-to-net carbohydrate ratio of about 0.01.

However, they can be a healthy carb source for professional athletes who train up to three times a day.

Some athletes combine keto and eating carbs with a method called carb-cycling.

They eat carbs occasionally since they think they might contribute to muscle recovery by replenishing carbohydrate stores (Murray et al. 2018²).

However, so-called loading days are unnecessary for muscle building as long as the protein supply is given (Koopman et al. 2007³).

Although the insulin levels increased by carbohydrates can help the muscles recover, they also help build body fat more efficiently (Ivy 2004⁴; Shah et al. 2011⁵).

Health Benefits of Sweet Potatoes

The orange interior of the sweet potato indicates its health potential since they contain carotenoids.

On the one hand, beta-carotene may boost vitamin A production, although this effect is often manageable (Lin et al. 2000⁶).

On the other hand, the carotenoids combined with antioxidants in sweet potatoes exert an effect that could reduce cancer and cardiovascular disease (Hou 2003⁷).

In this regard, purple Okinawa sweet potato is considered the tuber with the highest antioxidant content (Li et al. 2019⁸).

Moreover, studies suggest that sweet potatoes may improve glucose and lipid metabolism in people with insulin resistance and type 2 diabetes (Ludvik et al. 2008⁹; Kusano et al. 2000¹⁰).

In addition, sweet potato is one of the few carbohydrate sources free of lectins. If you want to eat carbohydrates occasionally, sweet potatoes are a healthy source.

Sweet Potatoes Are a Healthy Carb Source

Sweet potatoes are too high in carbs to fit into a keto diet. But if you want to replenish your glycogen stores occasionally, they are a great source of carbs.

Ultimately, they are lectin-free and can offer various health benefits.

Carbs in Sweet Potatoes: Keto FAQ

Is it OK to eat sweet potatoes on a low-carb diet?

Sweet Potatoes are too high in carbs to fit into a low-carb diet like keto.

How much sweet potato can I eat on keto?

You can eat one medium sweet potato (20 grams of net carbs) on keto if you do not consume other carbs. More sweet potatoes might kick you out of ketosis.

Is sweet potato a good carb?

Sweet potatoes are a good source of carbs.

How many net carbs are in a sweet potato?

There are about 20 grams of net carbs in a medium sweet potato.

Studies

¹Li A, Xiao R, He S, An X, He Y, Wang C, Yin S, Wang B, Shi X, He J. Research Advances of Purple Sweet Potato Anthocyanins: Extraction, Identification, Stability, Bioactivity, Application, and Biotransformation. Molecules. 2019 Oct 23;24(21):3816. doi: 10.3390/molecules24213816. PMID: 31652733; PMCID: PMC6864833.

²Murray B, Rosenbloom C. Fundamentals of glycogen metabolism for coaches and athletes. Nutr Rev. 2018 Apr 1;76(4):243-259. doi: 10.1093/nutrit/nuy001. Review. PubMed PMID: 29444266; PubMed Central PMCID: PMC6019055.

³Koopman R, Beelen M, Stellingwerff T, Pennings B, Saris WH, Kies AK, Kuipers H, van Loon LJ. Coingestion of carbohydrate with protein does not further augment postexercise muscle protein synthesis. Am J Physiol Endocrinol Metab. 2007 Sep;293(3):E833-42. doi: 10.1152/ajpendo.00135.2007. Epub 2007 Jul 3. PubMed PMID: 17609259.

⁴Ivy JL. Regulation of muscle glycogen repletion, muscle protein synthesis and repair following exercise. J Sports Sci Med. 2004 Sep;3(3):131-8. eCollection 2004 Sep. Review. PubMed PMID: 24482590; PubMed Central PMCID: PMC3905295.

⁵Shah PK, Mudaliar S, Chang AR, Aroda V, Andre M, Burke P, Henry RR. Effects of intensive insulin therapy alone and in combination with pioglitazone on body weight, composition, distribution and liver fat content in patients with type 2 diabetes. Diabetes Obes Metab. 2011 Jun;13(6):505-10. doi: 10.1111/j.1463-1326.2011.01370.x. PubMed PMID: 21272186; PubMed Central PMCID: PMC3580155.

⁶Lin Y, Dueker SR, Burri BJ, Neidlinger TR, Clifford AJ. Variability of the conversion of beta-carotene to vitamin A in women measured by using a double-tracer study design. Am J Clin Nutr. 2000 Jun;71(6):1545-54. doi: 10.1093/ajcn/71.6.1545. PMID: 10837297.

⁷Hou DX. Potential mechanisms of cancer chemoprevention by anthocyanins. Curr Mol Med. 2003 Mar;3(2):149-59. doi: 10.2174/1566524033361555. PMID: 12630561.

⁸Li A, Xiao R, He S, An X, He Y, Wang C, Yin S, Wang B, Shi X, He J. Research Advances of Purple Sweet Potato Anthocyanins: Extraction, Identification, Stability, Bioactivity, Application, and Biotransformation. Molecules. 2019 Oct 23;24(21):3816. doi: 10.3390/molecules24213816. PMID: 31652733; PMCID: PMC6864833.

⁹Ludvik B, Hanefeld M, Pacini G. Improved metabolic control by Ipomoea batatas (Caiapo) is associated with increased adiponectin and decreased fibrinogen levels in type 2 diabetic subjects. Diabetes Obes Metab. 2008 Jul;10(7):586-92. doi: 10.1111/j.1463-1326.2007.00752.x. Epub 2007 Jul 21. PMID: 17645559.

¹⁰Kusano S, Abe H. Antidiabetic activity of white skinned sweet potato (Ipomoea batatas L.) in obese Zucker fatty rats. Biol Pharm Bull. 2000 Jan;23(1):23-6. doi: 10.1248/bpb.23.23. PMID: 10706405.