What will cornstarch do to your body?

October 30, 2025 •

4 min read

According to the USDA, a single cup of commercial cornstarch contains 488 calories and nearly 117 grams of carbohydrates, but minimal other nutrients. In terms of what will cornstarch do to your body, its effects range from a rapid impact on blood sugar to contributing to caloric intake without significant nutritional value.

Quick Summary

Cornstarch is a processed, carbohydrate-rich powder that causes rapid blood sugar spikes due to its high glycemic index and lack of fiber. While it provides quick energy, it offers minimal nutrients and can contribute to weight gain if consumed excessively. Special medical conditions sometimes require its use to stabilize blood sugar, but large quantities, particularly if raw, can pose significant digestive and health risks.

Key Points

High Glycemic Impact: Cornstarch is a refined carbohydrate with a high glycemic index that can cause rapid blood sugar spikes.
Lacks Nutrients: It offers minimal nutritional value, providing mostly calories and carbs without significant protein, fiber, vitamins, or minerals.
Risks of Raw Consumption: Eating large amounts of raw cornstarch can cause digestive issues such as bloating, gas, and constipation.
Potential for Weight Gain: Its high calorie count and lack of satiating nutrients can contribute to weight gain if consumed excessively.
Associated with Pica: Compulsive cravings for large quantities of cornstarch may indicate amylophagia, a form of pica, often linked to nutritional deficiencies like anemia.
Specific Medical Use: Uncooked cornstarch is used under medical supervision for managing hypoglycemia in patients with Glycogen Storage Disease.
Naturally Gluten-Free: Cornstarch is a safe gluten-free alternative for thickening sauces for those with celiac disease, but cross-contamination is a risk with some brands.

Nutritional Profile: Empty Calories and High Glycemic Index

Cornstarch is a highly refined carbohydrate derived from the endosperm of corn kernels, and its nutritional profile is notably sparse. The wet milling process used to create it strips away most of the corn's beneficial components, including fiber, protein, and essential vitamins and minerals. A single tablespoon contains approximately 30 calories, with nearly all of them coming from carbohydrates, and offers zero grams of protein and fat. This lack of complementary nutrients like fiber means the body digests it very quickly.

The Impact on Blood Sugar

Because of its rapid absorption and lack of fiber, cornstarch has a high glycemic index (GI), a measure of how quickly a food raises blood sugar levels. When you consume cornstarch, especially in large amounts, it can lead to a quick and significant spike in blood glucose. This is particularly concerning for individuals with conditions like type 2 diabetes or insulin resistance, who need to carefully manage their blood sugar. Over time, frequent consumption of high-GI foods is linked to an increased risk of obesity, type 2 diabetes, and heart disease.

Weight Management and Metabolic Health

Regularly incorporating cornstarch-heavy foods into your diet can lead to weight gain. As a calorie-dense ingredient with little to no nutritional payoff, it can contribute significantly to overall caloric intake without promoting satiety. These 'empty calories' can displace more nutrient-dense foods from your diet, negatively impacting your overall nutritional status and metabolic health.

Potential Risks of Cornstarch Consumption

Beyond its effect on blood sugar and weight, there are other important health considerations associated with cornstarch. While small amounts used in cooking are generally safe, issues can arise with excessive consumption or eating it raw.

Digestive Issues

Difficulty digesting raw starch: Raw cornstarch is difficult for the human body to digest effectively. Consuming large, uncooked amounts can cause significant gastrointestinal distress.
Gas and bloating: Undigested starch molecules can ferment in the gut, leading to excess gas, bloating, and abdominal pain for some individuals.
Constipation: The low fiber content of cornstarch means it doesn't support healthy bowel movements, and large intakes could contribute to constipation.

Link to Pica (Amylophagia)

An intense, compulsive craving to eat pure starch, including raw cornstarch, is known as amylophagia. This behavior is a form of the eating disorder pica, which can also include cravings for non-food items like soil or ice. Amylophagia is often associated with nutritional deficiencies, most commonly iron-deficiency anemia, and can also have psychological components. Anyone with such cravings should seek medical evaluation to address potential underlying issues.

Comparison of Cornstarch with Other Starches


Feature	Cornstarch	Potato Starch	High-Amylose Cornstarch	Wheat Flour (Refined)
Nutritional Value	High in carbs, low in all other nutrients.	High in carbs, low in other nutrients, but some resistant starch.	High in resistant starch (prebiotic fiber).	Higher protein & fiber than cornstarch, but still refined.
Glycemic Index	High, causes rapid blood sugar spikes.	Lower than regular cornstarch, slower blood sugar impact.	Lower, beneficial for blood sugar control.	Lower than cornstarch, but still high GI.
Thickening	Opaque, stable under longer cooking times.	Creates clear, glossy sauces; sensitive to long heat.	N/A (medical/dietary use).	Opaque, less potent thickener, contains gluten.
Digestibility	Fast digestion, potentially causing spikes.	Ferments in colon (resistant starch) and digests slower.	Slow digestion, benefits gut health.	Varies, but slower than pure cornstarch due to other components.
Gluten Status	Naturally gluten-free.	Naturally gluten-free.	Naturally gluten-free.	Contains gluten.

Medical Uses for Cornstarch

Despite the risks of excessive consumption, uncooked cornstarch has a specific, medically supervised use for managing certain rare metabolic conditions. For individuals with Glycogen Storage Disease (GSD), consuming carefully measured doses of uncooked cornstarch can provide a slow, sustained release of glucose into the bloodstream. This helps prevent episodes of hypoglycemia (low blood sugar), particularly overnight, and is a vital component of their care plan. This is not a self-prescribed remedy and must be managed under strict medical guidance.

Conclusion

For most people, using small amounts of cornstarch in cooked foods for thickening is generally safe, though it offers minimal nutritional value. The key takeaway is moderation. Excessive intake can lead to blood sugar spikes, contribute to weight gain, and lead to digestive problems, especially if consumed raw. Anyone experiencing a compulsive craving for cornstarch should seek professional medical advice to rule out underlying nutritional deficiencies or eating disorders like pica. For those with specific medical conditions like GSD, cornstarch serves a targeted therapeutic purpose under expert supervision. The health effects of cornstarch on the body are a matter of dosage and context, with minimal nutritional benefits but notable risks when overused.

Frequently Asked Questions

No, consuming cornstarch in small, cooked quantities for thickening purposes is generally not harmful and is considered safe for most people.

As a calorie-dense and carbohydrate-rich food with little to no protein or fiber, cornstarch can contribute to weight gain if consumed in large quantities. However, it offers little nutritional value, so it is not a healthy way to add weight.

An intense, compulsive craving for starch, known as amylophagia (a form of pica), is often associated with nutritional deficiencies, most notably iron-deficiency anemia. It can also have psychological origins.

Diabetics and individuals with insulin resistance should consume cornstarch with caution. Due to its high glycemic index, large amounts can cause rapid blood sugar spikes. A healthcare provider should be consulted regarding appropriate intake.

The inflammatory effects of cornstarch are context-dependent. While small amounts are unlikely to cause inflammation, excessive consumption of high-carbohydrate, refined foods like cornstarch can contribute to chronic inflammation over time.

Healthier alternatives include arrowroot powder, ground flaxseed, chia seeds, and certain pureed vegetables for thickening. Whole grain flours, almond flour, or bean flour are better for baking as they contain more fiber and nutrients.

Yes, uncooked cornstarch is used under medical supervision to manage hypoglycemia in patients with Glycogen Storage Disease, providing a slow-release source of glucose. This is a specific therapeutic application, not a general health recommendation.