It is an tradition Mahatma Gandhi famously invoked as a tool of non-violent protest against British oppression.
The father of the nation's longest fast lasted 21 days, a stretch compared to the 24 hours that Narendra Modi will forego food and drink on Thursday.
But the prime minister will nonetheless become the most important participant in India's ongoing season of competitive fasting.
Mr Modi, who will be joined in his daylong fast by other parliamentarians of the Bharatiya Janata Party (BJP), said he would be protesting the opposition Congress party's behaviour in parliament.
The Congress, the BJP has claimed, disrupted proceedings so thoroughly during a recently concluded budget session that it became the least productive since 2000. Just one per cent of time was spent on legislation in the lower house, and 6 per cent in the upper house, according to figures compiled by PRS Legislative Research, a New Delhi-based institute.
Mr Modi's fast follows that of various Indian politicians over the last few weeks. Once Gandhi’s most potent weapon in his civil disobedience actions against the Raj, it has since become more of a political gimmick, critics say.
On Monday, Rahul Gandhi, the Congress' president, embarked on a daylong fast at Rajghat, Mahatma Gandhi's memorial in Delhi. The fast, Rahul Gandhi said, was to protest "the BJP's oppressive ideology" and its "violent" policies against lower castes and minorities.
Last week, the cadre of the All India Anna Dravida Munnetra Kazhagam (AIADMK), the party that rules Tamil Nadu, observed a daylong fast to demand the state’s share of water from the Cauvery river flowing from Karnataka, to the north.
On Friday, politicians from Andhra Pradesh also began an indefinite hunger strike in New Delhi, as part of an agitation for the state to receive more financial grants from the federal government.
Between 1918 and 1948, Gandhi fasted at least 15 times, in the hope that his moral force would quell religious riots, or support striking mill workers, or protest actions of the British.
He wrote, after the first such fast, that winning mill workers their rights in such a manner felt "not quite pure".
The frequent use of the fast by Gandhi and other freedom fighters impressed itself upon the Indian imagination. The fast was non-violent and easy to organise, and Gandhi linked the rejection of food to the self-abnegation of his own ascetic lifestyle.
In those years, however, Gandhi had few political options open to him. Circumstances in independent India, particularly for politicians who hold enormous power, are different.
"I take the view that [the protest fast] is not a legitimate form of political agitation when there are constitutional methods available," Nitin Pai, the director of the Takshashila Institution, a Bengaluru-based think-tank, said.
Mr Pai recalled the statement of another freedom fighter, B. R. Ambedkar, the architect of India's constitution.
After India became independent, Ambedkar argued that fasts and other techniques of protest belonged to the past. "These methods are nothing but the grammar of anarchy and the sooner they are abandoned, the better for us," he said.
The daylong fast that has become a gambit for modern politicians is also markedly different from Gandhi's indefinite fasts, during which he subsisted only water or dilute lemon juice. In comparison, over the course of just one day, a fast becomes an exaggerated way to skip lunch.
Politicians have ensured that they're well-fuelled nonetheless. Photographs showed several Congress officials tucking into a heavy breakfast before joining Rahul Gandhi in his fast on Monday. In Tamil Nadu, newspapers reported that AIADMK protesters were seen snacking surreptitiously; in one town, they even broke for lunch.
"It starts to become ridiculous," said Mytili Kumar, a Chennai-based hydrologist who studies the state’s river systems and the use of their water.
"The objective should have been to press the Modi government to release water from the Cauvery, as it's supposed to.
"Instead, with this kind of fast, it has been turned into a sideshow," she said. “It does nothing at all to put any sort of pressure on anyone."