Corn Nutrition: Calories, Carbs, Protein, and Fiber

This corn nutrition guide answers the questions people ask most: does corn have protein, carbs, and fiber, and how much of each. The short version is that whole corn is mostly carbohydrate, with a useful amount of fiber, a modest amount of incomplete protein, and a handful of vitamins and minerals worth having. Below are the numbers straight from the USDA, followed by what they mean for your plate, with a nudge toward whole, minimally processed, organic corn over the refined derivatives.

Corn nutrition facts per 100g and per ear

The figures below are for raw yellow sweet corn from USDA FoodData Central. A medium ear weighs about 102 grams of kernels, so its values run slightly higher than the per-100-gram column.

Put next to other everyday starches, corn is middle of the road. An ear has fewer calories than a medium baked potato and a bit more fiber than white rice, but it is far more carbohydrate-dense than non-starchy vegetables like zucchini or spinach. That is why nutrition guides file corn with the starches rather than with the greens, and why a balanced plate treats an ear of corn as the carbohydrate portion of the meal. These numbers hold for whole corn; the refined derivatives that fill packaged food keep the starch and lose most of the rest.

Does corn have carbs, and what about blood sugar

Corn is a starchy food. About 19 grams of the weight of a medium ear is carbohydrate, and roughly 6 grams of that is natural sugar, with about 2 grams of fiber. That makes corn more like a potato or a slice of bread than like a leafy green. The upside is the fiber, which slows how fast the starch becomes blood glucose. Whole sweet corn is usually rated at a low to moderate glycemic index, but published values range widely across varieties and cooking methods, so the safest move for anyone watching blood sugar is to keep portions in check and eat corn alongside protein or fat. Whole kernels do this far better than corn syrup or degermed cornmeal, which shed the fiber that steadies the rise.

Does corn have protein, and the lysine limit

Corn does have protein, about 3 grams per ear, but the quality is where it falls short. The main storage protein in corn is called zein, and zein is very low in two amino acids the human body needs from food, lysine and tryptophan. Research on maize describes its zeins as nearly devoid of lysine and tryptophan, which is why corn on its own is an incomplete protein. This is not a problem in a mixed diet. Beans, dairy, eggs, meat, or soy fill the gap, and the classic pairing of corn with beans supplies the lysine that corn lacks. Traditional cuisines across the Americas landed on that corn-and-bean combination long before anyone measured amino acids, and it remains a smart, low-cost way to build a fuller protein from whole plants.

How much fiber is in corn

A medium ear delivers about 2 grams of fiber, which is a fair amount for a side dish. Fiber supports regular digestion, helps steady blood sugar, and feeds gut bacteria. Whole-grain forms of corn, such as popcorn and whole cornmeal, carry more fiber than degermed products, where the bran and germ have been removed. If fiber is your goal, whole corn beats refined corn ingredients every time.

The form of corn changes the numbers a lot. Air-popped popcorn is close to pure whole grain, so cup for cup it is one of the higher-fiber ways to eat corn. Whole cornmeal keeps the bran and germ, while degermed cornmeal and corn grits lose much of the fiber and some minerals during milling. Sweet corn on the cob sits in the middle: less concentrated than dried corn products because it holds so much water, but still a genuine source of fiber. The lesson is the same one running through this guide: the less a corn food is processed, the more of its natural nutrition survives.

Vitamins, minerals, and antioxidants in corn

Corn is not a vitamin powerhouse, but it contributes several nutrients. It offers folate for cell growth, magnesium and potassium for muscle and nerve function, and a small amount of vitamin C. Its standout feature is color: yellow corn is one of the better food sources of lutein and zeaxanthin, two carotenoids that collect in the retina and filter blue light. Diets higher in these carotenoids are associated with a lower risk of age-related macular degeneration and cataracts, though supplements and food work differently and the eye benefit is a link rather than a guarantee.

Color is a clue to content. Yellow corn carries the lutein and zeaxanthin that white corn largely lacks, so if eye-supporting carotenoids matter to you, the yellow varieties are the better pick. Blue and purple corn add anthocyanins, the same family of pigments found in blueberries, and heirloom colored varieties are worth seeking out. Cooking changes a few numbers: heat lowers vitamin C and folate, so raw or lightly cooked corn holds more of those, while the minerals and fiber stay put. Boiling briefly, steaming, or grilling keeps more of the heat-sensitive vitamins than long simmering.

Is corn a vegetable, a grain, or a starch

The answer depends on the corn. Fresh sweet corn, the kind you eat off the cob or from a frozen bag, is classed as a starchy vegetable, since it is picked young while the kernels are soft and full of moisture. Dried field corn, harvested mature and hard for cornmeal, tortillas, grits, and popcorn, is classed as a whole grain. Either way, corn behaves like a starch on your plate, so it counts toward your carbohydrate servings rather than your leafy greens. Whichever form you choose, whole and organic beats refined, and buying organic also holds down the pesticide residues that come with conventional field corn. For the bigger picture on whether corn is a good or bad thing, see is corn bad for you. Corn contains no gluten, which matters for people with celiac disease, and you can read more on our page about whether corn is gluten free.