Ronald Reagan famously said once: "All great change in America begins at the dinner table."

What if the dinner plate of the guest of honor is empty?

Indian Prime Minister Narendra Modi is visiting the United States later this week, his first trip to this country after his party won a resounding victory in May. It is a visit that has been a long time coming and one that both nations hope will reboot U.S.-India relations.

Modi, who will address the United Nations General Assembly in New York on Saturday and speak before a large gathering at Madison Square Garden, was expected to attend a White House private dinner on Monday.

But now there is a new twist in the tale.

Modi, a devout Hindu, is observing the annual nine-day religious fast called Navratri, an auspicious period in the Hindu calendar that also marks the coming of autumn. No, this is not about dietary restrictions. For Modi, this is a strict no-food fast.

Fasting Hindus follow a fruit-only fast, or avoid meat, or get by with only one meal a day during this nine-day period. Some avoid onion, garlic and alcohol, as well. But Modi, who is a devotee of Hindu mother goddess Durga and a strict vegetarian and teetotaler, follows the strictest form of abstinence. Since the 1970s, he has observed water-only fasts.

In a blog in 2012, Modi wrote:

"Yes, I have been fasting during Navratri for over 35 years now. This fast is never to seek anything but an act of self-purification. Fasts such as this have been a source of strength, power and inspiration for me over the last many years."

"For Modi, this is not a religious ritual; it is a spiritual tool for introspection and cleansing," said Nilanjan Mukhopadhyay, author of the book "Narendra Modi: The Man, The Times." "For him, the fast is a personal journey inward. But knowing Modi, he will also convert it into an opportunity to tell Americans how strong he is from the inside."

Is this a dietary or diplomatic challenge for the White House? The White House staff has organized kosher meals and has catered to accommodate the dietary preferences of other world leaders before.

"Every detail of a state visit is addressed weeks in advance of a head of state's arrival by the U.S. State Department's Office of Protocol in collaboration with the advance team of the visiting country," said William Bushong, chief historian of the White House Historical Association. "This would include any dietary requirements."

"I can say that it never happened in the 11 years that I was there," said Walter Scheib, former White House chef. "I will also say that the White House staff and the first families will go out of their way to provide a gracious and hospitable visit to all guests. I'm certain that the prime minister will be cared for and all of his needs will be satisfied."

-By Rama Lakshmi