This is how Paramhansa Yogananda describes in chapter 46 of His 'Autobiography of a Yogi':
“Sir, we would like to know more of the fasting saint.”
"Her name is Giri Bala,” I my companions. “I first heard about her years ago from a scholarly gentleman, Sthiti Lal Nundy. He often came to the Gurpar Road home to tutor my brother Bishnu.”
"I know Giri Bala well,’ Sthiti Babu told me. ‘She employs a certain yoga technique which enables her to live without eating. I was her close neighbor in Nawabganj near Ichapur.1 I made it a point to watch her closely; never did I find evidence that she was taking either food or drink. My interest finally mounted so high that I approached the Maharaja of Burdwan2and asked him to conduct an investigation. Astounded at the story, he invited her to his palace. She agreed to a test and lived for two months locked up in a small section of his home. Later she returned for a palace visit of twenty days; and then for a third test of fifteen days. The Maharaja himself told me that these three rigorous scrutinies had convinced him beyond doubt of her non-eating state.’
"This story of Sthiti Babu’s has remained in my mind for over twenty-five years,” I concluded. “Sometimes in America I wondered if the river of time would not swallow the yogini3 before I could meet her. She must be quite aged now. I do not even know where, or if, she lives. But in a few hours we shall reach Purulia; her brother has a home there.”
By ten-thirty our little group was conversing with the brother, Lambadar Dey, a lawyer of Purulia.
"Yes, my sister is living. She sometimes stays with me here, but at present she is at our family home in Biur.” Lambadar Babu glanced doubtfully at the Ford. “I hardly think, Swamiji, that any automobile has ever penetrated into the interior as far as Biur. It might be best if you all resign yourselves to the ancient jolt of the bullock cart!”
"Giri Bala has never sought an inaccessible solitude for her yoga practices,” Lambadar Babu went on. “She has lived her entire life surrounded by her family and friends. They are all well accustomed now to her strange state. Not one of them who would not be stupefied if Giri Bala suddenly decided to eat anything! Sister is naturally retiring, as befits a Hindu widow, but our little circle in Purulia and in Biur all know that she is literally an ‘exceptional’ woman.”
The brother’s sincerity was manifest. Our little party thanked him warmly and set out toward Biur. We stopped at a street shop for curry and luchis, attracting a swarm of urchins who gathered round to watch Mr. Wright eating with his fingers in the simple Hindu manner.5 Hearty appetites caused us to fortify ourselves against an afternoon which, unknown at the moment, was to prove fairly laborious.
With feverish anticipation and suppressed rejoicing we stood before the open doors of the one blessed by the Lord’s ‘hungerless’ touch. Constantly agape were the villagers, young and old, bare and dressed, women aloof somewhat but inquisitive too, men and boys unabashedly at our heels as they gazed on this unprecedented spectacle.
"Soon a short figure came into view in the doorwayGiri Bala! She was swathed in a cloth of dull, goldish silk; in typically Indian fashion, she drew forward modestly and hesitatingly, peering slightly from beneath the upper fold of her swadeshicloth. Her eyes glistened like smouldering embers in the shadow of her head piece; we were enamored by a most benevolent and kindly face, a face of realization and understanding, free from the taint of earthly attachment.
"Meekly she approached and silently assented to our snapping a number of pictures with our ‘still’ and ‘movie’ cameras.6 Patiently and shyly she endured our photo techniques of posture adjustment and light arrangement. Finally we had recorded for posterity many photographs of the only woman in the world who is known to have lived without food or drink for over fifty years. (Therese Neumann, of course, has fasted since 1923.) Most motherly was Giri Bala’s expression as she stood before us, completely covered in the loose-flowing cloth, nothing of her body visible but her face with its downcast eyes, her hands, and her tiny feet. A face of rare peace and innocent poisea wide, childlike, quivering lip, a feminine nose, narrow, sparkling eyes, and a wistful smile.”
Mr. Wright’s impression of Giri Bala was shared by myself; spirituality enfolded her like her gently shining veil. She pronamed before me in the customary gesture of greeting from a householder to a monk. Her simple charm and quiet smile gave us a welcome beyond that of honeyed oratory; forgotten was our difficult, dusty trip.
The little saint seated herself cross-legged on the verandah. Though bearing the scars of age, she was not emaciated; her olive-colored skin had remained clear and healthy in tone.
"Mother,” I said in Bengali, “for over twenty-five years I have thought eagerly of this very pilgrimage! I heard about your sacred life from Sthiti Lal Nundy Babu.”
She nodded in acknowledgment. “Yes, my good neighbor in Nawabganj.”
"During those years I have crossed the oceans, but I never forgot my early plan to someday see you. The sublime drama that you are here playing so inconspicuously should be blazoned before a world that has long forgotten the inner food divine.”
The saint lifted her eyes for a minute, smiling with serene interest.
“Baba (honored father) knows best,” she answered meekly.
I was happy that she had taken no offense; one never knows how great yogis or yoginis will react to the thought of publicity. They shun it, as a rule, wishing to pursue in silence the profound soul research. An inner sanction comes to them when the proper time arrives to display their lives openly for the benefit of seeking minds.
“Mother,” I went on, “please forgive me, then, for burdening you with many questions. Kindly answer only those that please you; I shall understand your silence, also.”
She spread her hands in a gracious gesture. “I am glad to reply, insofar as an insignificant person like myself can give satisfactory answers.”
“Oh, no, not insignificant!” I protested sincerely. “You are a great soul.”
“I am the humble servant of all.” She added quaintly, “I love to cook and feed people.”
A strange pastime, I thought, for a non-eating saint!
“Tell me, Mother, from your own lipsdo you live without food?”
“That is true.” She was silent for a few moments; her next remark showed that she had been struggling with mental arithmetic. “From the age of twelve years four months down to my present age of sixty-eighta period of over fifty-six yearsI have not eaten food or taken liquids.”
“Are you never tempted to eat?”
“If I felt a craving for food, I would have to eat.” Simply yet regally she stated this axiomatic truth, one known too well by a world revolving around three meals a day!
“But you do eat something!” My tone held a note of remonstrance.
“Of course!” She smiled in swift understanding.
“Your nourishment derives from the finer energies of the air and sunlight,7 and from the cosmic power which recharges your body through the medulla oblongata.”
“Baba knows.” Again she acquiesced, her manner soothing and unemphatic.
“Mother, please tell me about your early life. It holds a deep interest for all of India, and even for our brothers and sisters beyond the seas.”
Giri Bala put aside her habitual reserve, relaxing into a conversational mood.
“So be it.” Her voice was low and firm. “I was born in these forest regions. My childhood was unremarkable save that I was possessed by an insatiable appetite. I had been betrothed in early years.
“‘Child,’ my mother often warned me, ‘try to control your greed. When the time comes for you to live among strangers in your husband’s family, what will they think of you if your days are spent in nothing but eating?’
“The calamity she had foreseen came to pass. I was only twelve when I joined my husband’s people in Nawabganj. My mother-in-law shamed me morning, noon, and night about my gluttonous habits. Her scoldings were a blessing in disguise, however; they roused my dormant spiritual tendencies. One morning her ridicule was merciless.
“‘I shall soon prove to you,’ I said, stung to the quick, ‘that I shall never touch food again as long as I live.’
“My mother-in-law laughed in derision. ‘So!’ she said, ‘how can you live without eating, when you cannot live without overeating?’
“This remark was unanswerable! Yet an iron resolution scaffolded my spirit. In a secluded spot I sought my Heavenly Father.
“‘Lord,’ I prayed incessantly, ‘please send me a guru, one who can teach me to live by Thy light and not by food.’
“A divine ecstasy fell over me. Led by a beatific spell, I set out for the Nawabganjghat on the Ganges. On the way I encountered the priest of my husband’s family.
“‘Venerable sir,’ I said trustingly, ‘kindly tell me how to live without eating.’
“He stared at me without reply. Finally he spoke in a consoling manner. ‘Child,’ he said, ‘come to the temple this evening; I will conduct a special Vedic ceremony for you.’
“This vague answer was not the one I was seeking; I continued toward the ghat.The morning sun pierced the waters; I purified myself in the Ganges, as though for a sacred initiation. As I left the river bank, my wet cloth around me, in the broad glare of day my master materialized himself before me!
“‘Dear little one,’ he said in a voice of loving compassion, ‘I am the guru sent here by God to fulfill your urgent prayer. He was deeply touched by its very unusual nature! From today you shall live by the astral light, your bodily atoms fed from the infinite current.'”
Giri Bala fell into silence. I took Mr. Wright’s pencil and pad and translated into English a few items for his information.
The saint resumed the tale, her gentle voice barely audible. “The ghat was deserted, but my guru cast round us an aura of guarding light, that no stray bathers later disturb us. He initiated me into a kriatechnique which frees the body from dependence on the gross food of mortals. The technique includes the use of a certain mantra8 and a breathing exercise more difficult than the average person could perform. No medicine or magic is involved; nothing beyond the kria.“
Maharshi Devraha Baba also is believed to had attained this by making His breafh flow through Ira and Pingala Nadi as the youtube video says.
And no, it does not seem to be for a specific purpose.In sanskrit there is a saying:
meaning: whatever is subject to others is grief and to the self is joy.
So if one can overcome hunger or need of taking external food, why whould he want to take it again? I do not think someone having lobha or greed can ever attain this state and so resuming food intake I think is out of question.