Is Corn Keto Friendly
It feels like corn is “everywhere”. So, the question of whether corn is keto-friendly is not necessarily a straightforward one.
As a starting point if you are wondering whether you can eat corn and all its by-products on a ketogenic diet?
The answer is no for corn on the cob and for sweet corn.
When you look at refined and processed food like tortillas, taco shells, cornflakes, chips, popcorn, flour, fillers, and so on the ideal answer is no.
If you are asking about corn starch and high fructose corn syrup it is still no.
Baby corn – maybe!
The simple answer is that corn is a grain and that the carbohydrates are too high.
I know corn on the cob may be considered a vegetable by some, but even if you consider it a vegetable it is a starchy vegetable high in carbohydrates with a low to moderate amount of fiber.
For all the “obvious” corn products it is easiest to just stay away from them.
However, the case against corn is not as cut and dry as the case against rice.
When it comes to corn, do your research and decide what is best for you. If you decide to eat it, observe how it makes you feel and make sure that it doesn't cycle you in and out of ketosis.
Now, let's investigate!
As always, we'll start with the amount of carbohydrates and glycaemic index.
Then we'll consider the other reasons why you may want to avoid corn when you follow a ketogenic diet.
Total and Net Carbs
Like always, these numbers are an indication and sources differ on the exact amounts.
Always check the macros with your favorite carb checker.
Our main sources for checking macros are:
Total carbs 32 grams per cup or 16 per ½ a cup with 2 grams of fiber leaving a cup of corn with 30 grams of net carbs.
If you consider 1/2 a cup to be a portion you are looking at 15 net carbs per portion.
Cob of Sweet Corn (1 Ear)
1 Cob is roughly equal to 2/3 of a cup, so has 21 grams of carbohydrates and 20 net per cob.
Total 24 grams per bowl with only 1 gram of fiber leaving a bowl of corn flakes with 23 grams of net carbs.
If you are following a strict ketogenic diet this is more than your total carbohydrates for the day.
An additional problem with corn flakes is that you'll probably want to eat it with milk and sugar or some sweetener. Both of which will substantially increase the number of carbs in your first meal of the day.
So many of our favorite Mexican dishes has corn as a base.
There are 20 grams of carbs in 2 medium tortillas with 3 grams of fiber. So, your tortilla meal starts off with 17 grams of net carbs before you add a filling.
3 shells (which is considered one portion) has 20 grams of total carbs with 1 gram of fiber.
1 ounce of nacho chips have 18 grams of net carbs.
As you can see the carbs are high and not suitable for a ketogenic diet.
And that is just the first part of the problem.
You should also be concerned about the other unhealthy ingredients used when these highly processed staples are made.
Around 20 net carbs per 1 oz.
These are pretty standard numbers when it comes to corn products. See below with the snacks as well.
So generally, the base of your meal or one small snack will use up your carb allocation for the day.
We do like our corn snacks, don't we?
Here is a breakdown of the net carbs in some of our favorite snacks:
- Corn nuts for 1 oz - 19 grams
- Puffs for 1 oz - 19 grams
- Blue corn chips per 1 oz -16 grams
- Other chips per 1 oz - a minimum of 16
I am listing these really to make a point. If you are following a keto diet, you won't want to eat any foods that are this processed.
This is a discussion on its own.
There are roughly 6 grams of carbs per cup of popped corn. A serving is considered to be 2 1/2 cups.
So 15 grams per serving.
Baby corn is very different to normal corn in that it is harvested before the stalk matures.
With regular corn the stalk is not edible, whereas with baby corn it is.
Because it is harvested while it is so young both the starch and sugar components are lower than mature corn.
The total carbs per cup is 8, with 4 of those being fiber leaving 4 grams of net carbs per cup.
This is most definitely the lowest carb corn that you'll find.
Glycaemic Index (GI)
So now that we are clear on the carbohydrates, what does the GI look like?
In summary it is medium to high. Obviously the less processed the more medium the GI.
In a nutshell, expect corn to raise blood sugar but not as much as with rice and other grains.
For more about GI and GL and the impact of carbs on ketosis, go here.
The GI is as follows:
- Cooked sweet corn - 50's
- Cornflakes - 80's
- Tortilla - 40's
- Taco Shells - 60's
- Popcorn - 60's
- Crackers, nuts, and chips - Unsure, likely to be above 60
- Baby corn - Unknown but likely to be lower than regular corn.
Two good sources for GI's:
60 Common foods - Harvard Medical school
Database - Sydney University
So, the carbs are generally high and the GI medium to high.
Both reasons why corn is not okay for keto, but there are other factors to consider...
It contains phytic acid
Phytic acid is considered an anti-nutrient as it may impair the body’s ability to absorb minerals like iron, zinc, magnesium, and calcium.
(All nutrients that are critically important when you follow a ketogenic diet.)
Read more about them here.
It is susceptible to fungi growth
Have you ever looked at a cob of corn and seen that it looks moldy?
This fungi produces toxins known as mycotoxins.
Generally, these mycotoxins don't seem to be a big problem in first world countries where the consumption of corn is not a main staple.
However, anybody who has issues with candida, or any fungal infections may want to keep this in mind.
Up to 92% of maize crops in the United States are genetically modified.
So, if you try to live GMO-free, corn is not a viable food source.
It is everywhere
For a comprehensive list of food items that include corn, you may find this list from the University of Rochester Golisano children’s hospital insightful.
Because it is everywhere, it is easy to overeat and it accounts for lots of hidden carbs that you don't even know that you are consuming.
I am having a small portion.
If you are having baby corn, go for it.
I eat it only very occasionally.
Again, if you can work it into your macros go for it. If you are following a Banting diet, you'll find that corn is on the dark orange list. So, it is acceptable to eat occasionally.
I am carbo loading for an event.
Then choose your preferred medium to high carbohydrate food and enjoy. Do yourself a favor and eat it as unprocessed as possible. To carbo load, there may be better options.
Let's have a look at a few alternatives...
Low Carb Low Starch Vegetables
Unlike with rice there just aren't that many alternatives for cob on the corn.
The best substitute is low starch vegetables like:
The carb count for all these veggies is low and can all easily fit into your macros. The GI for all these veggies is 15 or less.
They are all quick to prepare and the perfect low carb side dish.
For a full list of keto-friendly veggies, check out our shopping list.
For processed foods try these...
Substitutes for Processed Corn Products
When you look for substitutes, read the labels carefully. Just because a product description on Amazon claims that a product is keto, doesn't mean it is.
It is probably easiest to make you own as you'll know exactly what is in your breakfast cereal.
If you are looking for a crunchy cereal, then try this recipe from The Big Man's World.
I haven't found a really good healthy cereal to buy yet. When I do, I'll add it here.
But if you'd like a low carb granola, try this one...
Make your own healthy tortillas. They are easy to make. Here is my favorite recipe.
Or try these from Julian Bakery...
Once you've settled into a keto diet, you probably won't be snacking.
But if you are looking for low carb snacks, then this is the ultimate list and also where you will find our 9 favorite popcorn alternatives.
The objective of a ketogenic diet is to enter a state of ketosis. Ideally you want to stay in ketosis and not cycle in and out.
To maintain ketosis, you’ll want to eliminate as much corn from your diet as possible.
In conclusion to the question - Is corn keto or is it bad for you?
The simple answer is no it is not keto, it is likely to spike your blood sugar and it is most likely genetically modified.
You can eat a portion of baby corn and be okay.
Similarly, with the question:
Are corn flakes okay on keto?
No, it is not keto-friendly.
One bowl of dry corn flakes has more than 20 grams of net carbohydrates, so your total daily allocation gone with breakfast.
They also have a high GI, so in all likelihood will spike blood sugar.
And if you are asking about all your Mexican favorites, sorry no. They are high in carbohydrates and highly processed.
And corn-based snacks?
No! They have too many carbs and are highly processed. They contain many ingredients you don't want to eat on a keto diet.
Keto Stamp of Approval?
Corn is not keto approved.
Although it should occasionally be okay on a low carb diet.
We Need Your Help
We would love to hear from you.
If you have questions about any of your favorite foods, leave us a comment.
We are working on answering as many "Can I eat this on my keto diet?" questions as possible and want to address the most asked questions first.
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