Nature has created all kinds of food and everyone has to live on foods appropriate to his constitution. Each man, each people, each society has to choose the appropriate foods that will give the best results.
Modern scientists consider meat as more nourishing food but also as more unwholesome one. It contains more toxins and one becomes rough and cruel. Herbivorous animals being vegetarians came to a higher consciousness than the carnivorous. As one slays them they feel a specific kind of fear that provokes the formation in their organisms of certain toxins.
Alimentation is a science dealing with transformation of energies from one condition to another.
Alimentatin represents a transformation of the rough energy in a spiritual one. When you finish your meal you will begin to sing and thus you will transform the mental energy in spiritual one.
As to the prayer, it is a law for the transformation of mental energies.
The disciples are absolutely forbidden to overeat. When they feel their meal most tasty they have to stop eating. A man in good health is moderate with food and his stomach is always in good condition.
Mastication has to be calm and energetic, food has to be reduced to gruel and then to be sent to the stomach.
When you masticate your food, the invigorating energy passes through your tongue and is accumulated in the nervous system. More you masticate your food more energy you accumulate in your nervous system.
Through the tongue the energy is transmitted to the brain and then to the heart.