Corn mainly contains carbs, with starch being the largest component. Sweet corn has more sugar but is low on the glycemic index, so it doesn't rapidly raise blood sugar levels.
Corn is rich in fibre, especially insoluble types like hemicellulose. A medium bag of cinema popcorn provides a significant portion of the daily fibre recommendation for both men and women.
It offers moderate protein levels, mostly in the form of zeins. While zeins lack some essential amino acids, they are useful in making things like adhesives and coatings.
Corn's vitamin and mineral content varies by type. Popcorn is generally rich in minerals, while sweet corn tends to have higher levels of various vitamins.