I don't have a microwave at school, or thermasHow do I keep it hot?
There are 2 types of fiber that our bodies need: Soluble and InsolubleSoluble or water soluble is found primarily in plant cellsGood sources are beans, lentils, fruits, veggies, oat branInsoluble are indigestible parts that pass thru us unchangedThese keep the digestive system healthyConsuming these will help your stomach problemsWheat or rice bran, skins of fruits and veggies, nuts, seeds, whole grain foodsRead labels carefully and only buy breads that list WHOLE wheat or WHOLE grain as a main ingredientAn excellent choice are sprouted breads such as Ezekiel, usually found in the freezer sectionMost commercial breads are made with flour which has the bran and germ removed, in turn, removing the fiber along with beneficial vitaminsI never eat fast food so I can't help u much there.
Wrap it in aluminum foil and then paper towelsGood luck! (: