Throughout a grueling schedule that features the United Nations General Assembly, a rally of Indian Americans at New York's Madison Square Garden and talks with Obama in Washington, the devout Hindu will abstain from food.

In keeping with the habits of a lifetime, Modi will restrict himself to a ‘liquid diet’ throughout the Navratri festival, when India's majority Hindus worship mother goddess Durga in all her manifestations.

"He will only consume lemonade with some honey and a cup of tea every day," a senior official in Modi's office in New Delhi told Reuters.

"He has been fasting for the last four decades and does not want to change this pattern even while he is travelling," added the official, who spoke on condition of anonymity.

Navratri, derived from the ancient Sanskrit words 'nine nights', falls this year from September 25 to October 3. The festival spans Modi's first trip to the United States since he triumphed in a general election in May.

It culminates on the tenth day, known as Dussehra, which marks the victory of good over evil.

Millions of Hindus fast, pray and dance to please the mother goddess during Navratri. Some restrict their diet to fruit and vegetables while spurning meat, onions and garlic. Others, like Modi, a strict vegetarian, do not eat at all.

"He wakes up at 4 am, meditates, prays and carries his own bottle of lemonade with him," said another government official who has worked closely with Modi for 12 years.

"Doctors had suggested that he should consume fruits and more juices but he has refused to make any dietary additions during the Navratri celebrations," said a senior minister in western state of Gujarat, where Modi served as Chief Minister for more than a decade.

"In US you will not see him having dinner or lunch with Obama," said the state minister, who is also close to Modi.

Another Indian government source said the White House had been informed of Modi's dietary requirements. US embassy in New Delhi declined to comment.

US officials have indicated that President Barack Obama would not treat Modi to a state dinner, as Modi did not hold the rank of head of state. Obama did, however, accord this honour to Modi's predecessor, Manmohan Singh.

As a young man, Modi left home to seek enlightenment, finding inspiration from the writings of philosopher-monk Swami Vivekananda, who propagated the Hindu faith at the Parliament of Religions in Chicago in 1893.

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