On 28/01/2000 a question was asked about an interesting subject. "Nowadays, food is being sold in restaurents, hotels, and food stalls. Was there by any chance cooked food being sold in the olden days?".
Like we had so many bachelors like me now, i presume there would have been many in those days. So, they would have to have depended upon some external sources for food atleast in some situations.
In my great grandfather's times atleast it was considered wrong to take money (or any return) from people for food. Of course where you ate was strongly bound by caste definitions. So if you are a bachelor or out of town and a brahmin, you ate at those chatrams for charity or found another known brahmin's house to eat at, of course this slowly came down to relatives and then distant relatives and stopped ultimately. It was that way among other non brahmin castes also. Another reason why this system sustained was most of rice and grain came from village fields in those days and nobody paid to buy it. Commercial eataries and eating out only started full fledge after people sold their lands and had to go for jobs full time.
My grandmother used to say every visitor was considered Rama and you got treated like Sabari treated Rama, with the greatest respect and offered whatever you had for food. Those who took advantage of this were labelled 'sapattu ramans', hence the name came about I believe.