After entertaining at least one guest and looking after him properly, a person should sit for his meals in a happy frame of mind. He should not eat with wet hands or feet, nor should he eat wearing only a single piece of cloth. While taking food, he should sit facing east or north. He should not eat facing a corner or during sunrise or sunset or when in a melancholy mood. He should sprinkle a few drops of sanctified water on the food and then only begin eating. Except fruits, roots, fried and dried articles, chutneys and sweets, no items carried over from the previous day should be eaten. One should not eat leftover items except ghee, honey, curds and flour-based foodstuffs. For some more about ahara niyamam read http://anudinam.org/2012/06/11/srivaishnava-ahara-niyamam/
First, sweet items should be taken, followed by salty and sour items. Bitter, spicy or pungent items should be reserved for the end. Further, one who takes liquid items first, then solid food and rounds them off again with liquid food will never fall ill or have gastric problems. Finally, a person should never criticize the food he is taking. He should not chatter while eating, but concentrate on eating.
Now to the verses for digestion: After dining in the above-mentioned manner, a person should sit facing east or north for a while and, with a contented mind, recite the following verses.
Chanting these six verses, one should gently massage one’s stomach. Then there will be no problems like indigestion etc., provided the precautions mentioned earlier were taken while eating.