Can You Eat Onions on Keto
I remember the days when I was doing Weight Watchers that onions have more carbs than you think so they had a higher Points value than other vegetables. It’s not surprising that when switching to keto or low carb eating, I had the same questions about them. So, can you eat onions on keto? Well, yes and no.

Are onions keto friendly?
Onion is technically a root vegetable because it comes from the ground. Most root vegetables are higher in carbs and therefore many root veggies aren’t so keto-friendly. However, like with so many ingredients, there are ways you can make them work on this diet. But you have to do so thoughtful.
The short answer to that is no. Onions are not keto friendly. The average large onion contains 0 grams of fat, 14 grams of carbohydrates and 2 grams of protein. That’s an awful lot of carbs for a single vegetable.
There are other higher carb vegetables, too. This includes avocados and Brussels sprouts.
Low carb vegetables
Consider how onions compare with other lower-carb vegetables. This is using a one-cup measurement and according to the USDA:
- Red bell peppers: 5.5 grams
- Broccoli: 4.75 grams
- Asparagus: 5 grams
- White mushrooms: 2 grams
- Zucchini: 4 grams
- Spinach: 6.75 grams
- Cauliflower: 5 grams
- Kale: 6.25 grams
- Cucumber: 2.5 grams
According to harvard.edu, a keto diet really shouldn’t exceed 50 grams daily. And let’s face it, trying to balance out 50 grams of carbs daily can be a bit tricky, especially if you want to indulge in tasty veggies like onions. Onions do have some health benefits and a whole lotta flavor.
Some health benefits of onions
I’d be remiss if I didn’t at least share with you the health benefits of onions. Regardless of the fact they aren’t completely keto friendly, you can still sneak some into your keto diet. Word of caution though, red onions have a slightly higher sugar count. If a recipe calls for red onions, add sparingly.
So before you discount onions altogether from your daily diet, let’s look at some health benefits first.
- Loaded with antioxidants
- Can benefit heart health
- Help control blood sugar
- Can boost digestive health
Just to name a few! This article from healthline.com goes into great depth about the health benefits and why you should eat more onions. So there are some benefits in trying to make them work with your low carb eating or keto diet.
Can you eat onions on keto?
We’ve already established that yes you can but they aren’t so keto friendly. So how do we work around that? First of all, you have to understand that there are different kinds of onions. And each variety has different carbohydrate levels. I’m talking about white onions, yellow onions, red onions and green onions, also known as scallions.
I think the most important thing to keep in mind is that if you are just starting your keto diet or perhaps restarting and not quite in ketosis yet, you should definitely stay away from onions or other questionable foods that are on the fine line of keto friendly foods.
While some foods are not entirely keto-friendly but still ok to consume moderately, if you are in the early stages of getting into ketosis, you must avoid them all and stay strictly with keto-friendly foods only.
That answers the no part, you shouldn’t eat onions on keto. Unless you’re in keto maintenance mode.
Recipe: How to Make Caramelized Onions on Keto
Are green onions keto friendly?
Are green onions keto friendly? A lot friendlier than all the other onions! A cup of green onions or scallions has just about 7 grams of carbs. While that may seem like a lot, given other lower-carb vegetables, when have you ever eaten or used an entire cup of scallions? I know I haven’t.
They are also an excellent source of soluble fiber. A few other health benefits of green onions are:
- High in vitamin K
- Excellent source of vitamin C
- High in fibre (helps you feel fuller longer)
- Protects your cells against damage
Red onions

Let’s take red onions for example. So many recipes call for them but they aren’t so keto friendly because of their high sugar content. They are delicious, though, probably because of that aforementioned sugar content.
Yellow and white onions
When providing the original carb content for onions, I was using USDA data for yellow or white onions. They are sometimes called sweet onions. While they don’t have as much sugar — or as many carbs — as red onions, that count is definitely higher than green onions or scallions.
Keto substitutes for onions
Unfortunately, there is no healthy swap for onions like there is for potatoes. In this latter example, you would substitute cauliflower. But we’re talking onions here.
A good keto substitute for red onions or even yellow or white onions would be green onions or scallions. With so many recipes calling for onions, it would be a shame to not be able to eat any at all because of the keto diet.
You can use green onions in just about any recipe. They won’t give off the same sweet taste as those other onion varieties. But you will still get an onion flavor that you desire.
So can you eat onions on keto?
Yes. In moderation and only if you aren’t trying to get into ketosis. Once you have already achieved ketosis state, though you don’t want to kick yourself out of it, it’s ok to introduce veggies like onions, in small quantities, to your favorite dishes.
Being on the keto diet doesn’t mean you have to sacrifice flavor, especially the deliciousness of onions. It just means you have to be a tad more careful when eating some of your favorite veggies.