The Upanishadic advice is to eat food that keeps your body healthy. Treat food as a type of medicine.
After saying thrice, ‘I have renounced, I have renounced, I have
renounced’, he shall take up the bamboo staff and don the loin-cloth,
uttering the mantra: ‘Let all beings be devoid of fear. Everything
originates from me. You are my friend and [you] protect me. You are
the strength, my friend. You are the vajra of Indra that killed Vrtra.
Be pleasant to me and remove all my sins.’ He shall pertake of food as
if it were medicine. He shall eat as if taking medicine. He shall eat
as and when food is obtained. ‘Oh [disciples], protect brahmacarya,
non-injury, non-possession and truth with care.’ 1
1 The outer and inner aspects of these qualities are: brahmacarya
(outer) = celibacy, (inner)=the dwelling of the mind on Brahman;
ahimsa=not injuring others, non-injury of oneself;
aparigraha=non-possession of anything other than what is needed for
bare subsistence, non-concern with all but Brahman;
satya=truthfulness, realization of the true nature of the Self.
Arunyupanishad translated by Prof A A Ramanathan
Chandogya Upanishad says that some spiritual aspirant takes a vow to not eat fish and meat for a year or to permanently stop eating non-veg food. The exact shloka is:
He who thus knows this Yajnayajniya Saman, woven in the limbs of the
body, is endowed with all the limbs, and is not crippled in any limb;
he reaches the full length of life, lives gloriously, becomes great
with offspring and cattle and great also with fame. His holy vow is
that he should not eat fish and meat for a year, or rather, he should
not eat fish and meat at all.
Chandogya Upanishad 2.19.2
Swami Vivekananda has also discussed the question of food for Bhaktas.
The question of food has always been one of the most vital with the
Bhaktas. Apart from the extravagance into which some of the Bhakti
sects have run, there is a great truth underlying this question of
food. We must remember that, according to the Sankhya philosophy, the
Sattva, Rajas, and Tamas, which in the state of homogeneous
equilibrium form the Prakriti, and in the heterogeneous disturbed
condition form the universe — are both the substance and the quality
of Prakriti. As such they are the materials out of which every human
form has been manufactured, and the predominance of the Sattva
material is what is absolutely necessary for spiritual development.
The materials which we receive through our food into our
body-structure go a great way to determine our mental constitution;
therefore the food we eat has to be particularly taken care of.
However, in this matter, as in others, the fanaticism into which the
disciples invariably fall is not to be laid at the door of the
And this discrimination of food is, after all, of secondary
importance. The very same passage quoted above is explained by
Shankara in his Bhâshya on the Upanishads in a different way by giving
an entirely different meaning to the word Âhâra, translated generally
as food. According to him, "That which is gathered in is Ahara. The
knowledge of the sensations, such as sound etc., is gathered in for
the enjoyment of the enjoyer (self); the purification of the knowledge
which gathers in the perception of the senses is the purifying of the
food (Ahara). The word 'purification-of-food' means the acquiring of
the knowledge of sensations untouched by the defects of attachment,
aversion, and delusion; such is the meaning. Therefore such knowledge
or Ahara being purified, the Sattva material of the possessor it — the
internal organ — will become purified, and the Sattva being purified,
an unbroken memory of the Infinite One, who has been known in His real
nature from scriptures, will result."
These two explanations are
apparently conflicting, yet both are true and necessary. The
manipulating and controlling of what may be called the finer body, viz
the mood, are no doubt higher functions than the controlling of the
grosser body of flesh. But the control of the grosser is absolutely
necessary to enable one to arrive at the control of the finer. The
beginner, therefore, must pay particular attention to all such
dietetic rules as have come down from the line of his accredited
teachers; but the extravagant, meaningless fanaticism, which has
driven religion entirely to the kitchen, as may be noticed in the case
of many of our sects, without any hope of the noble truth of that
religion ever coming out to the sunlight of spirituality, is a
peculiar sort of pure and simple materialism. It is neither Jnâna, nor
Bhakti, nor Karma; it is a special kind of lunacy, and those who pin
their souls to it are more likely to go to lunatic asylums than to
Brahmaloka. So it stands to reason that discrimination in the choice
of food is necessary for the attainment of this higher state of mental
composition which cannot be easily obtained otherwise.
The Complete Works of Swami Vivekananda, Volume 3, Bhakti Yoga, The Method and the Means
A note of caution
Food suggested in any Hatha Yoga book is not accepted by all Yogis. This is because some Yogis think that Hatha yoga is bad for spirituality.
It is bad according to Sri Ramakrishna.
A DEVOTEE: "Sir, what is hathayoga like?"
MASTER: "A man practising hathayoga dwells a great deal on his body.
He washes his intestines by means of a bamboo tube through his anus.
He draws ghee and milk through his sexual organ. He learns how to
manipulate his tongue by performing exercises. He sits in a fixed
posture and now and then levitates. All these are actions of prana. A
magician was performing his feats when his tongue turned up and clove
to the roof of his mouth. Immediately his body became motionless.
People thought he was dead. He was buried and remained many years in
the grave. After a long time the grave somehow broke open. Suddenly
the man regained consciousness of the world and cried out, 'Come
delusion! Come confusion!1 (All laugh.) All these are actions of
"The Vedantists do not accept hathayoga. There is also rajayoga.
Rajayoga describes how to achieve union with God through the mind — by
means of discrimination and bhakti. This yoga is good. Hathayoga is
not good. The life of a man in the Kaliyuga is dependent on food."
The Gospel of Sri Ramakrishna, With the devotees at Dakshineswar (II), December 9, 1883
MANILAL: "And what about hathayoga?"
MASTER: "The hathayogis identify themselves with their bodies. They
practise internal washing and similar disciplines, and devote
themselves only to the care of the body. Their ideal is to increase
longevity. They serve the body day and night. That is not good.
The Gospel of Sri Ramakrishna, The master in various moods, October 2, 1884