It depends ...
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Corn (one 154g serving) contain 29g of Carbohydrate (with some being from fiber) and so it is considered a Keto food, if you count it as part of the 25g limit of carbs you'll have per day.
But here's the kicker; some of that carbohydrate (5.0g) is fiber which means that a whole serving has about 25 grams of carbs in it. That's right at the limit of how many carbs you can eat on a Keto diet.
So if you don't mind consuming all of your carbs as corn then corn is a Keto food. Most people don't consider it one but it all depends on how you decide to consume it.
Corn has almost no fat and a small amount of protien which means when you eat it you'll basically have a modest insulin spike along with the carb load.
Controlling insulin is key when it comes to the Keto diet and adding in corn ensures that you are as safe as can be with that food group.
Eat and be healthy.
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