Polenta is low-calorie, with only 70 calories per 100-gram serving. It is also a source of protein and fiber, as well as iron and vitamin A.
Some brands are also fortified with additional nutrients, so check the package to be sure. Polenta is gluten-free, and, although it does have carbohydrates, the kind it contains are complex carbohydrates, which means these carbs are broken down slowly and therefore will give you energy for a long time after you've consumed the polenta.
It also helps to maintain your blood sugar levels, so you don't feel that crash two to three hours after eating a meal with lots of carbs.