Amazing Onions

Onions are popular root vegetables commonly used in soups, roasts, sandwiches, and salads. But are onions keto?

Yes, onions are keto-friendly if you consume them in moderation and offer various nutrients that support overall health, making them an excellent addition to any keto meal plan. 

Discover onion nutrition facts and learn about the best onions to eat on a low-carb diet.

How many carbs are in onions?

According to the U.S. Department of Agriculture (USDA), 100 grams of raw onion contains 9.3 grams of total carbohydrates and 1.7 grams of fiber.

To calculate the net carb count of raw onions, subtract fiber from the total carb count. This leaves approximately 7.6 grams of net carbs per 100 grams of onion.

However, some onion varieties have fewer carbs than others, which makes them more suitable for a ketogenic diet. 

Onion nutrition facts 

There are many types of onions, including white, yellow, and green onions. Other popular varieties include purple and red onions and Vidalia onions, a particularly sweet type of onion. 

Though they’re all rich sources of essential vitamins and minerals, the nutritional profile of different onion varieties can vary greatly. 

Here’s the nutritional value of different types of onions per 100 grams.

White onion: 

• 36 calories

• 0.89 g protein

• 0.13 g fat

• 7.7 g total carbs

  • 1.2 g fiber

  • 6.5 g net carbs

Red onion:

• 44 calories

• 0.94 g protein

• 0.1 g fat

• 9.9 g total carbs

  • 2.2 g fiber

  • 7.7 g net carbs

Yellow onion:

• 38 calories

• 0.83 g protein

• 0.05 g fat

• 8.6 g total carbs

  • 1.9 g fiber

  • 6.7 g net carbs

Green onion:

• 32 calories

• 1.83 g protein

• 0.19 g fat

• 7.3 g total carbs

  • 2.6 g fiber

  • 4.7 g net carbs

Sweet onion:

• 32 calories

• 0.8 g protein

• 0.08 g fat

• 7.5 g total carbs

  • 0.9 g fiber

  • 6.6 g net carbs

Onions are also rich sources of nutrients, including:

• Vitamin B6

• Vitamin C

• Folate

• Magnesium 

• Potassium

Watch the video below to learn more about the amazing health benefits of onions. 

Are onions keto-friendly?

Yes, you can enjoy onions on keto despite having a slightly higher carb content than other keto-friendly vegetables. 

However, it’s best to consume them in moderation, as eating too many onions may exceed your daily net carb limit. Include onions in your net carb count to avoid getting kicked out of ketosis. 

5 benefits of onions

While onions add flavor to various dishes, they’re also rich in vitamins and minerals that promote health and may reduce disease risk.

Here are five incredible benefits of onions.

1. Promote gut health

Onions are a rich source of prebiotic fiber, which feeds the beneficial bacteria residing in the gut. When gut bacteria break down and ferment probiotic fibers, they release short-chain fatty acids (SCFAs). 

Research published in Foods found that SCFAs play a crucial role in gastrointestinal health, support optimal digestion, and may relieve constipation. 

The study also found that SCFAs can reduce inflammation in the gastrointestinal tract associated with inflammatory bowel disease (IBD), help manage obesity, and promote proper energy metabolism. 

2. May help prevent hair loss

Onions contain sulfur, a mineral that promotes hair growth and supports the development of healthy hair follicles. Sulfur also boosts collagen production and helps prevent its breakdown, which is vital for healthy skin cells and hair shaft formation.

Additionally, onions can inhibit androgens from being converted into dihydrotestosterone (DHT), a powerful form of testosterone, which may contribute to patterned baldness and alopecia. 

“Onion juice is a potent natural inhibitor of 5-alpha reductase, an enzyme that converts testosterone into DHT linked to hair loss,” explains Dr. Berg. 

To promote hair growth, it’s recommended to mix onion juice and water in a one-to-one ratio. Apply the mixture to your hair, let it sit for 15 minutes, then rinse thoroughly.

3. Potential anti-cancer effects

The Allium genus of flowering plants, which includes onions, garlic, chives, leeks, shallots, and scallions, has been studied for its potential anticancer properties. 

Onions and garlic, in particular, have been shown to help slow down or even prevent the spread of cancer cells by initiating apoptosis, a process of programmed cell death.

A study published in Cancer Prevention Research found that consuming onions and other Allium vegetables can reduce the risk of various cancers, including stomach, colorectal, esophageal, and prostate cancer.

4. Support immune functions

Onions have antibacterial and antifungal effects that may reduce the risk of viral diseases and infections. 

Research published in the Scholars Journal of Applied Medical Sciences found that the extract of various types of onions, including white and red onions, was effective against Escherichia coli (E. coli), Salmonella, and Methicillin-resistant Staphylococcus aureus (MRSA). 

5. May improve bone density

Eating onions may improve bone density by enhancing antioxidant activity in the body and reducing oxidative stress. 

Oxidative stress results from a cellular imbalance between antioxidants and free radicals, which are highly volatile compounds that can damage cell organelles and trigger inflammation. Bone matrix is particularly susceptible to oxidative stress which can increase the risk of bone loss and osteoporosis. 

Research shows that women 50 years and older who consume onions have a 20 percent reduced risk of hip fractures compared to those who don’t eat onions.

The study published in Menopause also found that “...bone density increased as the frequency of onion consumption increased. Individuals who consumed onions once a day or more had an overall bone density that was five percent greater than individuals who consumed onions once a month or less.”

Keto-friendly recipes with onions

Incorporate more onions into your diet without breaking ketosis with these four mouthwatering keto-friendly recipes.

Keto Onion Rings

This Keto Onion Rings recipe is a healthier, low-carb version of the classic fried appetizer. 

Made with pork rinds and coconut flour instead of bread crumbs and wheat flour, this recipe will give you that satisfying crunch without the added carbs.

These onion rings are also baked instead of fried in seed oils, which are linked to chronic inflammation and weight gain. 

Keto French Onion Chicken Casserole

If you’re a fan of French onion soup, you’ll enjoy this quick and easy casserole dish. 

Made with caramelized onions, pepper jack, and cheddar cheese, Keto French Onion Chicken Casserole is a cheesy, crispy dinner baked to perfection in 20 minutes. 

Pepper/Onion Omelet

With only five simple ingredients and ready to eat in 15 minutes, this Pepper/Onion Omelet is a great way to break your fast when you’re short on time.

This recipe calls for colorful bell peppers, chopped onion, coconut oil, and butter to create a nutritious meal rich in healthy fats, vitamins, and minerals.

Keto-Friendly Onion Crackers

If you have access to a food dehydrator, these Keto Friendly Onion Crackers are a crunchy cracker alternative that won’t interfere with ketosis. 

Made with chopped yellow onion, ground flaxseeds, sunflower seeds, and olive oil, this recipe is packed with omega-3 fatty acids that promote eye and brain health.

What type of onions should you choose? 

The best onions for those on keto are the varieties with the lowest amount of sugars and carbohydrates. 

Here’s a list of onions ranked by net carb count per 100 grams according to data from the USDA:

• Green onions: 4.7 grams 

• White onions: 6.5 grams  

• Sweet onions: 6.6 grams 

• Yellow onions: 6.7 grams 

• Red or purple onions: 7.7 grams 

White, yellow, and green onions are the most keto-friendly options due to their distinct flavors and lower carb content. However, you can enjoy any variety of onions as long as you include them in your daily net carb count.

Additionally, opt for organic onions when possible to avoid exposure to genetically modified organisms (GMOs), synthetic herbicides and pesticides. 

Organic farmers are prohibited from using chemical herbicides, like glyphosate, which is heavily sprayed in commercial onion fields. Indirect glyphosate ingestion has been linked to reproductive issues, cancer, and other health problems.

Organic onions are also more nutrient-dense than conventional produce and have been shown to contain higher amounts of antioxidants, which help prevent oxidative stress and may reduce disease risk. 

Key takeaways

Are onions keto-friendly? Yes, onions are a healthy addition to a ketogenic diet. 

However, they do contain some carbs and should be enjoyed in moderation. Including onions in your net carb count is vital to avoid exceeding daily carbohydrate limits.

Onions are rich in antioxidants, sulfur, and prebiotic fiber that may help reduce cancer risk while supporting immunity, strong bones, and gut health.

FAQ

1. Are onions high in carbs?

Yes, onions contain more carbs than other keto-friendly vegetables. On average, 100 grams of onion have 7.6 grams of net carbs. 

However, most people don’t consume whole onions, and incorporating moderate amounts of onion into a keto diet is unlikely to interfere with ketosis. 

2. How much onion can you eat on keto?

Onions should be consumed in moderation on keto. Onion varieties with a lower carb count, such as green onions, contain 4.7 g net carbs per 100 grams and can be enjoyed in larger amounts. 

However, higher-carb options such as red, yellow, and sweet onions can have as much as 7.7 g net carbs per 100 grams, and can exceed your daily net carb count if consumed in excess. 

3. Which onions are best for keto?

Green and white onions are the most keto-friendly as they contain 4.7 g and 6.5 g of net carbs per 100 grams, respectively. 

However, all onions are suitable for a low-carb diet in small amounts. Many keto dieters enjoy onions by tracking carbohydrate consumption to avoid exceeding their daily carb limits.

4. What are the top health benefits of onions?

Onions have been shown to have potential anti-cancer effects, antibacterial properties, and antifungal benefits. 

They’re also rich sources of prebiotic fiber, vitamins, minerals, and antioxidants that promote gut health, hair growth, and bone mineral density.

Sources

1. https://fdc.nal.usda.gov/fdc-app.html#/food-details/170000/nutrients 

2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9498509/ 

3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4366009/ 

4. https://www.saspublishers.com/media/articles/SJAMS_411D_4128-4133.pdf 

5. https://pubmed.ncbi.nlm.nih.gov/19240657/