If your sub doesn't fill you up and doesn't have any flavor, it's your own fault. You can add as many things as you want to them, whether it be tons of cheese and veggies, extra meat, or many of their flavor-packed sauces and condiments. You can put as many veggies and condiments as you like on your sandwich for no additional charge and if you really do pack on the veggies the sandwich will be filling (especially if you get a footlong).