In metro areas, there are a large number of migrants who are looking for ready to eat food since preparing food for a single person is time consuming and tedious. So there are a large number of fast food outlets selling food for Rs 20 or 30 each, the food is safe to eat.
In comparison, in smaller cities and towns there are very few migrants, so there are very few fast food outlets. In some areas, the fast food outlet will have extremely spicy food or only sweet food which is not suitable for older citizens