The nutrition analysis of polenta is like this
for 50g (about 1,6oz or 1/3cup)
Energy 180 kcal
Protein 4 g
Fat 0.5 g
Fibre 1.3 g
Sugars 0.5 g
Sodium 2 mg
This is an analysis of regular polenta, if you can find whole grain or polenta taragna (specialty of valtellina, made with buckwheat mixed in) the nutritional value is a little higher, especially fibre content, plus they have more robust flavour. (they are usually not precooked though so it takes a lot more time, about 30-40 minutes with continuous stirring)
Also it can be said that polenta is very filling, so it will satisfy you quicker, and let's say takes less than pasta or rice to fill you up.
I don't see why not with the addition of garlic, flavour of polenta is quite neutral so there is a lot of room for you to play with with your imagination.