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Is Cornstarch Keto-Friendly?

Cornstarch on a kitchen counter

So, Is Cornstarch Keto-Friendly? Not quite.

With its high-carb content, cornstarch doesn't quite fit the bill for a typical ketogenic diet.

This staple ingredient, often used as a thickening agent in various dishes, is often a point of contention for those following a low-carb lifestyle.

In this article, we delve into the nitty-gritty of cornstarch's carb content, its impact on a ketogenic diet, and explore potential keto-friendly alternatives.

Whether you're a seasoned keto enthusiast or new to the low-carb life, this comprehensive breakdown is sure to provide valuable insights and practical solutions.


  • Is cornstarch keto-friendly? The short answer is no.
  • Cornstarch is high in carbs and has a high glycemic index, making it a poor fit for a ketogenic diet.
  • Its minimal nutritional benefits, combined with a lack of beneficial vitamins, proteins, and significant dietary fiber, further limits its utility on a keto diet.

Is Cornstarch Keto-Friendly?

Cornstarch, when examined through the lens of a keto-friendly perspective, does not quite fit the bill. The ketogenic diet, primarily focused on high-fat, moderate-protein, and very low-carb intake, finds little room for cornstarch in its regimen.

The reason for this disfavor towards cornstarch in a keto diet lies in its high carbohydrate content. A serving size of 100g of cornstarch contains a significant 90.37g of net carbs. This amount of carbs is quite high when considering the ketogenic diet, which typically limits total daily carb intake to between 20 and 50 grams. Presented with these figures, it's apparent that even a small portion of cornstarch can max out or even exceed your daily carb limit on a strict keto diet.

Can You Have Cornstarch On a Strict Keto Diet?

In the context of a strict ketogenic diet, incorporating cornstarch into meal plans is not advisable due to its high net carb content. A strict keto diet usually targets a daily carb intake of less than 20g, a limit quickly breached by even a modest amount of cornstarch.

Even for those following a more flexible keto or low-carb diet, where daily net carb intake is allowed in the range of 30-50g, cornstarch remains problematic. An average serving could almost entirely consume the daily carb allowance, leaving little room for nutritional diversity.

To successfully adhere to a ketogenic lifestyle, managing carb intake is critical. Various tools and apps can assist in tracking carb intake meticulously. By doing so, a person can maintain a clear overview of daily carb consumption, helping to avoid inadvertent overages. However, considering cornstarch's high carb content, it is challenging to incorporate it without disrupting ketosis, the metabolic state at the heart of the ketogenic diet.

Carbs In Cornstarch

Cornstarch carries a hefty carbohydrate load, with 90.37g net carbs per 100g. This high carb content makes it a challenging food item to incorporate into a low-carb or ketogenic diet, which generally aims for a much lower daily carb intake.

Moreover, cornstarch has a high glycemic index of 85 [source]. The glycemic index classifies foods based on how much they raise blood glucose levels. Values are grouped into three categories: low (55 or less), medium (56 to 69), and high (70 to 100). With its high glycemic index, cornstarch is quickly digested and absorbed, leading to rapid spikes in blood sugar levels, which is generally not desirable in a ketogenic diet. Foods with a lower GI digest slowly, leading to a steady rise in blood sugar levels, whereas foods with a high GI are quickly digested, causing a rapid spike.

Cornstarch Nutrition Facts

Cornstarch is a food rich in carbohydrates. In every 100g portion, it provides 91.27g of carbohydrates, out of which 90.37g are net carbs. It also contains a small amount of dietary fiber, 0.9g to be exact.

In terms of protein, cornstarch is not a significant source, providing only 0.26g per 100g. Similarly, its total lipid (fat) content is negligible, with only 0.05g in a 100g portion.

Looking at its micronutrient profile, cornstarch contains small amounts of various minerals. It has 2.0mg of calcium, 0.47mg of iron, 3.0mg of magnesium, 13.0mg of phosphorus, 3.0mg of potassium, 9.0mg of sodium, and 0.06mg of zinc. It also provides trace amounts of copper and manganese, and a tiny quantity of selenium.

The food also contains a very small amount of choline and various types of fatty acids. Among these are saturated fatty acids, such as SFA 16:0 and SFA 18:0, as well as monounsaturated and polyunsaturated fatty acids.

Cornstarch has a low but diverse amino acid profile, containing small amounts of tryptophan, threonine, isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, and serine.

Nutrient NameAmount and Unit per 100 g
Net Carbs90.37g
Total lipid (fat)0.05g
Carbohydrate, by difference91.27g
Fiber, total dietary0.9g
Calcium, Ca2.0mg
Iron, Fe0.47mg
Magnesium, Mg3.0mg
Phosphorus, P13.0mg
Potassium, K3.0mg
Sodium, Na9.0mg
Zinc, Zn0.06mg
Copper, Cu0.05mg
Manganese, Mn0.053mg
Selenium, Se2.8µg
Choline, total0.4mg
Fatty acids, total saturated0.009g
SFA 16:00.009g
SFA 18:00.001g
Fatty acids, total monounsaturated0.016g
MUFA 18:10.016g
Fatty acids, total polyunsaturated0.025g
PUFA 18:20.025g
Aspartic acid0.02g
Glutamic acid0.053g
Nutritional data is sourced from the US Department of Agriculture's FoodData Central system. Please see Cast Iron Keto's editorial and research standards for more information.

Health Implications of Cornstarch on a Keto Diet

Including cornstarch in a keto diet poses a significant challenge for maintaining ketosis due to its high carbohydrate content and high glycemic index, potentially causing rapid spikes in blood sugar levels. This could disrupt the metabolic state that a ketogenic diet aims to achieve.

Looking into its nutritional content, cornstarch does offer some nutrients. It contains trace amounts of minerals like calcium, magnesium, phosphorus, and iron. However, these quantities are minimal and do not contribute significantly to daily nutrient requirements.

Keto-Compatible Alternatives for Cornstarch

  1. Almond Flour: With a significantly lower carb content than cornstarch, almond flour can serve as a keto-friendly thickening agent in sauces, gravies, and bakes. It not only offers a nutty flavor but also brings in fiber, healthy fats, and protein, enhancing the nutritional profile of dishes.
  2. Coconut Flour: Another low-carb alternative, coconut flour is highly absorbent and can be used sparingly as a thickener. It's particularly effective in baked goods and provides a mild coconut flavor. Plus, it has the advantage of being rich in fiber and healthy fats.
  3. Xanthan Gum: This is a potent thickener derived from fermented sugars, and only a tiny amount is needed. It's effectively carb-free and can be used in a wide range of recipes from soups to baked goods to smoothies.

Concluding Thoughts on Cornstarch

From our discussion, it's clear that cornstarch does not align well with the low-carb principles of a ketogenic diet. Its high carbohydrate content and high glycemic index make it a challenging food to incorporate without disrupting ketosis. While cornstarch contains minimal amounts of some minerals, its lack of significant dietary fiber, beneficial vitamins, and proteins limits its nutritional value.

However, it's worth noting that cornstarch's thickening properties are often desirable in cooking and baking. Instead of cornstarch, use keto-compatible alternatives like almond flour, coconut flour, or xanthan gum. These alternatives not only bring their unique flavors and characteristics to your dishes but also offer added nutritional benefits, making them great substitutes when following a ketogenic lifestyle.

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Cast Iron Keto's Editorial and Research Standards

Certain rare or exotic food items may not have nutritional profiles in the FoodData Central database. If an exact match is not found in the FoodData Central database, then, the Cast Iron Keto team utilizes a three-prong approach to provide readers with the closest relevant nutritional data, where possible.

First, in the event that nutritional profiles for a rare or exotic food item is not available in the FoodData Central database, we investigate alternative names for that particular food item and use that data, when possible. Second, in cases where no alternate names exist, Cast Iron Keto will use nutritional data for a close relative or similar food item. Finally, if no close relatives or similar items exist, we refrain from publishing nutrient data tables.

When making dietary or health decisions based on FoodData Central's data, we suggest readers consult with a nutritionist or other health experts, particularly if the food in question has a significant role in your diet or if you are using the food item to treat any health disorder(s).

Furthermore, it is important to note that even if a close relative or similar item is used to approximate the nutritional data, different food items can have varying levels of nutrients due to factors such as soil quality, farming practices, and regional differences.


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Frequently Asked Questions

No, cornstarch is not ideal for a ketogenic diet owing to its high carbohydrate content and high glycemic index.

Cornstarch has minimal nutritional benefits. It contains trace amounts of minerals like calcium, magnesium, phosphorus, and iron, but lacks significant dietary fiber, beneficial vitamins, and proteins.

Yes, there are several keto-friendly alternatives to cornstarch such as almond flour, coconut flour, or xanthan gum, which offer added nutritional benefits.