yāta-yāmaḿ gata-rasaḿ
pūti paryuṣitaḿ ca yat
ucchiṣṭam api cāmedhyaḿ
bhojanaḿ tāmasa-priyam

Translation of Bhagavad Gita 17.10

Food prepared more than three hours before being eaten, food that is tasteless, decomposed and putrid, and food consisting of remnants and untouchable things is dear to those in the mode of darkness.

Commentary by Sri A.C. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya:

The purpose of food is to increase the duration of life, purify the mind and aid bodily strength. This is its only purpose. In the past, great authorities selected those foods that best aid health and increase life’s duration, such as milk products, sugar, rice, wheat, fruits and vegetables. These foods are very dear to those in the mode of goodness. Some other foods, such as baked corn and molasses, while not very palatable in themselves, can be made pleasant when mixed with milk or other foods. They are then in the mode of goodness. All these foods are pure by nature. They are quite distinct from untouchable things like meat and liquor. Fatty foods, as mentioned in the eighth verse, have no connection with animal fat obtained by slaughter. Animal fat is available in the form of milk, which is the most wonderful of all foods. Milk, butter, cheese and similar products give animal fat in a form which rules out any need for the killing of innocent creatures. It is only through brute mentality that this killing goes on. The civilized method of obtaining needed fat is by milk. Slaughter is the way of subhumans. Protein is amply available through split peas, dal, whole wheat, etc.

Foods in the mode of passion, which are bitter, too salty, or too hot or overly mixed with red pepper, cause misery by reducing the mucus in the stomach, leading to disease. Foods in the mode of ignorance or darkness are essentially those that are not fresh. Any food cooked more than three hours before it is eaten (except prasadam, food offered to the Lord) is considered to be in the mode of darkness. Because they are decomposing, such foods give a bad odor, which often attracts people in this mode but repulses those in the mode of goodness.

Remnants of food may be eaten only when they are part of a meal that was first offered to the Supreme Lord or first eaten by saintly persons, especially the spiritual master. Otherwise the remnants of food are considered to be in the mode of darkness, and they increase infection or disease. Such foodstuffs, although very palatable to persons in the mode of darkness, are neither liked nor even touched by those in the mode of goodness. The best food is the remnants of what is offered to the Supreme Personality of Godhead. In Bhagavad-gita the Supreme Lord says that He accepts preparations of vegetables, flour and milk when offered with devotion. Patram puspam phalam toyam. Of course, devotion and love are the chief things which the Supreme Personality of Godhead accepts. But it is also mentioned that the prasadam should be prepared in a particular way. Any food prepared by the injunctions of the scripture and offered to the Supreme Personality of Godhead can be taken even if prepared long, long ago, because such food is transcendental. Therefore to make food antiseptic, eatable and palatable for all persons, one should offer food to the Supreme Personality of Godhead.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

Yata yamam means food which has remained three hours (yamam) after cooking, or in other words, that which has become cold after cooking. Gata rasam means food from which the natural taste is missing, or has been extracted, or such items as the skin and seed of the ripe mango. Puti means bad smelling. Paryusitam means over-ripe. Ucchistam refers to the leftovers other than that from the guru or other similar persons. Amedyam means inedible items such as kalanja. From reviewing the list of foods, one should conclude that those interested in their own welfare should partake of sattvika foods. The vaisnavas however reject any food not offered to the Lord, even if it is sattvika food. Food offered to the Lord is dear to the devotees beyond the gunas. This is understood from the Bhagavatam.

Commentary by Sri Ramanuja of Sri Sampradaya:

17.10 Stale (Yatayamam) means that food which has lost its original state, being kept for a long time. Tasteless (Gatarasam) means that which has lost its natural taste. Putrid (Puti) means emitting a bad smell. Decayed (Paryusitam) means acquiring a rancidity by lapse of time. Refuse (Ucchistam) means the food that has remained over after being partaken by persons other than Gurus, etc. Unclean (Amedhyam) is that which is not fit for offering in sacrifice or worship. The meaning is that, being unfit for offering in worship, they cannot become the sacrificial remainder. Foods of this kind which promote the growth of Tamas are dear to those who are characterised by Tamas. Food (Bhojana) means that which is eaten. Tamasik food promotes further increase of Tamas. Hence, those persons who care for their own welfare by the growth of Sattva, should eat food charaterised by Sattva.

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

Foods that bequeath longevity, full of energy, bestow good health and vigour with happiness and satisfaction are relished by those in sattva guna the mode of goodness. Such foods in sattva guna particularly increase life and are juicy, savoury, rich and nourishing, like invigorating serum which remains long in the body and are agreeable and pleasing to the palate. Foods of this type which are chewed, licked, sucked and drunk are relished by those situated in sattva guna.

Foods that are excessively bitter, sour, pungent, salty, spicy, dry or burning are very much liked by those situated in raja guna the mode of passion. Such foods cause pain even while eating them which leads to distress of the body, misery, depression and subsequent disease and sickness all produced by these foods.

Food cooked more than three hours before, that is cold, tasteless, without aroma, stale, decomposed and foods that are amedhyam or forbidden for offering to the Supreme Lord such as meat, fish, fowl, eggs, wine, alcohol, garlic, onions and mushrooms which come from fungus and are impure are preferred by those in tama guna the mode of ignorance.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

Eating foods that are of sattva guna the mode of goodness are pleasurable. Joyfulness is the immediate result. Whatever continues to be pleasurable is joyous to hrdya the heart. Even if all foods are cooked they all do not get digested the same. Ghee and honey are absorbed into the body directly, fruits take an hour to digest and vegetables and grains up to six hours. Some foods although bitter are agreeable to health such as kerala or bitter melon and some foods although sour like yoghurt are agreeable to health if not taken at night. Both of these are of sattva or goodness. Such is the nature of the pious and the saintly and that nature is maintained by the intake of foods that are sattva. The Shabda Niranya states: Hridyam is that which is pleasing to the heart and makes one desire for more. Pleasure is what is pleasing for the moment. Sukham or happiness is that which continues to keep one joyous long after the activity has ended. That food which retains its agreeability even after consuming repeatedly is rasyam which is delicious and nutritious.

But when foods are excessively bitter, spicy, salty. sour, pungent, etc. and result in discomfort and misery culminating in sickness and disease they are of raja guna the mode of passion. The food which is eaten more than three hours after it is cooked is known as yatama. When the food is tasteless it is also called yatayama. Food that once was flavourful but later becomes later has no taste is known as gatarasyam. The Suddhasastra states that one devoted to serving the Supreme Lord Krishna or any of His authorised incarnations should thoroughly understand the nature and quality of food.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

Lord Krishna commences with the three-fold divisions of foods with the words ayuh-sattva meaning promoting longevity. Food that promotes spiritual knowledge which is the quality of intelligence has been corroborated previously in chapter XIV.XVII stating that: Wisdom verily arises out of sattva guna the mode of goodness. Whereas greed and lust are the by products of raja guna the mode of passion and lethargy and nescience is produced by those in tama guna the mode of ignorance. The word bala meaning strength and refers to food that gives the power to perform one’s duty. Foods that are pleasant to eat, that bestow mental tranquillity, that are sustaining and easily digestible, that are nourishing and their essence remains invigorating the body even after digested are the foods which are dear to those endowed with the qualities of sattva guna.

Foods which are extremely acidic, salty, spicy, pungent and bitter such as azadirachta indica or burning such as chillies which burn the mouth, throat and stomach simply bring about distress and misery which leads to sickness and disease. The prefix aty meaning extremely at the end of the word lavanaty meaning extremely bitter applies to all the descriptions up to vidadhinah which means burning. Such foods are dear to those characterised with raja guna.

Foods which are half cooked, insipid, stale, tasteless, polluting, contaminated or leftovers from someone and foods that are forbidden to offer to the Supreme Lord such as meat, fish, fowl, eggs, onions, garlic, mushrooms, wine, alcohol, etc. are the foods of choice for those situated in tama guna.

The obvious conclusion is that those who are spiritually motivated and desire their best self interests should conscientiously avoid all foods characterised by raja guna and tama guna and resort exclusively to foods that are of sattva guna.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

17.10 Bhojanam, food; which is yata-yamam, not properly cooked [Yata-yamam lit. means ‘crooked three hours ago’, that which has lost its essence; but here it is translated as ‘not properly cooked to avoid tautology, for the next word gata-rasam, too, means lacking in essence.-Tr.] (-because food that has lost its essence is referred to by the word gatarasam-); gata-rasam, lacking in essence; puti, putrid; and paryusitam, stale, cooked on the previous day and kept over-night; and even ucchistam, ort, remnants of a meal; and amedhyam, that which is unfit for sacrifice;- this kind of food is tamasa-priyam, dear to one possessed of tamas. Now then, sacrifices of three kinds are being stated:

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

17.7-10 Aharah etc. upto tamasapriyam. What is old : that for which [three] yamas have elapsed [after cooking].

Sanskrit Shloka Without Transliteration Marks:

yata-yamam gata-rasam
puti paryusitam ca yat
ucchistam api camedhyam
bhojanam tamasa-priyam

Sanskrit to English Word for Word Meanings:

yāta-yāmam — food cooked three hours before being eaten; gata-rasam — tasteless; pūti — bad-smelling; paryuṣitam — decomposed; ca — also; yat — that which; ucchiṣṭam — remnants of food eaten by others; api — also; ca — and; amedhyam — untouchable; bhojanam — eating; tāmasa — to one in the mode of darkness; priyam — dear.