Eating and drinking from a gold or silver container or dish is forbidden. Prophet Muhammad (SAW) stated that: whoever eats or drinks from gold and silver containers here, will be deprived of the gold and silver containers of heaven in the hereafter. It is recommended to eat and feed others delicious foods, even if you must pay particular attention to its excellence and hygiene. Forbidding oneself delicious foods is deplored, but one must always ensure the food is halal and should never eat to an extent that hinders the worship of God.
One must not constantly aspire and endeavor to feed himself/herself, as animals do, rather the purpose of eating should be attaining power for worship, and one must only eat to an extent that the food is not wasted upon him/her, for God does not like wasters. Imam Sadiq (AS) said: many times we fed people of the exquisite breads and porridges and delicious puddings and we said whenever God grants us abundance we too serve in abundance, and whenever God gives in scarcity we too serve scarcely. Imam Sadiq (AS) also identified three things which a pious man will not be called to account for in the hereafter: the food he has ate, clothes that he has worn and a devout woman who has been his companion. The Imam (AS) further identified four things that God detests and one of those things is eating while full.
Prophet Muhammad (SAW) said: a pious man eats with one stomach but a non-believer eats with seven stomachs, meaning he eats a lot. Imam Musa al Kazim (AS) said that: if people are moderate in their eating, their bodies will always be healthy. Imam Sadiq (AS) said that humans must inevitably eat something to survive but when eating must designate a portion of the stomach for food and another portion for breathing and should not attempt to fatten themselves as if they are animals waiting to be killed and eaten. He added that when the stomach is full it causes corruption and revolt and said that all diseases and illness come from overeating. Prophet Jesus (AS) said: Oh Israelites, do not eat unless you are hungry, and when you are hungry do not eat until you are full, for your necks will thicken and your waists will fatten and you will forget your God.
The Time and Manner of Eating:
Traditionally breakfast was eaten after sunrise and nothing else was eaten during the day until after the Isha prayers and only small bites were taken and properly chewed. One should not look to the face of others or eat hot foods and even if the food is hot one should not blow on it but let it cool itself. One should not use bread (for other than eating) or clean the bone or eat using less than three fingers or extend a hand towards others and should lick the fingers and dish clean.
There is a saying attributed to Imam Ali (AS) that the last meal of Prophets (AS) was after the Isha prayers, so it should not be neglected as it will ruin the body. There is another saying that neglecting the meal at the end of the night will make one aged and old and when that happens one must eat before sleeping to be able to fall asleep easier and that will give him pleasant breaths and positive attitudes.
The Manner of Eating:
According to tradition it is recommended to eat with the right hand while sitting on both knees, and not to eat while lying down. It is also inappropriate to eat alone or sit casually or eat while walking. However it is tradition to eat with the servants and workers and to sit on the floor. Imam Musa al Kazim (AS) said that a meal is complete when it is halal, there are many hands extended towards it, it is started in the name of God and God is thanked at its end.
The Recitation of Mealtime Prayers:
It is related that the Prophet Muhammad (SAW) said that when a meal is set four thousand angels encircle it and if someone says “In the Name of God” the angels pray so God may bless you and your meal, then they turn to Satan and say be gone you obscene creature for you have no power over these people; and if after the meal someone gives thanks to God, the angels will say these were a people who God blessed and they were thankful to their Lord.
However, if the meal is not started with God’s name, the angels invite Satan to join the meal, and if the meal is cleared and God has not been thanked the angels will say, these were a people who God blessed and they forgot about their Lord.
The Virtue and Manner of Hosting Pious Guests:
This saying is correctly attributed to Imam Sadiq (AS): that if your pious brother comes to your house do not ask him if he has had anything to eat today, but bring him whatever you have prepared for he who gives all he has is truly generous and benevolent. In a another tradition he has said: if you spend 1000 dinars on a meal and a pious person eats from that meal, you have not wasted anything. And in another place he has said that: I enjoy sharing a bite to eat with my pious brother more than freeing slaves.
Source: Allamah Muhammad Baqir Majlesi, Helyat ul-Mottaqin.