Occupy D.C. protesters (from left) Sam Jewler, Kelly Mears and Adrian Parsons. (Ricky Carioti/WASHINGTON POST)

But not until after breakfast.

Adrian Parsons, Sam Jewler and Kelly Mears began their fast at noon at McPherson Square Park in Northwest Washington.

View Photo Gallery: Two groups of demonstrators have entrenched themselves in Freedom Plaza and McPherson Square downtown. Dozens were arrested after blocking traffic Dec. 7.

Their last meal consisted of carrot juice, spinach juice, stir-fried vegetables and tofu.

At a news conference Thursday afternoon, protesters said they will sustain their hunger strike until D.C. is granted full voting representation in Congress. A shelter was erected for the three men to use during their hunger strike.

While the trio is part of the Occupy D.C. group that has been camped out in McPherson Square since early October, this is not an official Occupy D.C. event.

Dubbed “Occupy the Vote D.C.,” the group calls for full legislative and budget autonomy as well as full representation and voting rights in Congress, according to the group’s tumblr page.

Occupy protesters erect a shelter that will be used for a hunger strike by three protesters at the Occupy D.C. encampment. (Ricky Carioti/WASHINGTON POST)

How long will the hunger strike last? The strikers said they are prepared to stop eating until their demands are met.

But it is more likely that the duration of the fast will depend on how long the strikers can withstand starvation.

“Sixty days, give or take, is the rule of thumb,” according to a Slate article on the subject.

Fasting becomes dangerous in less than a week and then “it’s all downhill after Week 3.”

Here are a few of history’s famous fasters and how long their hunger strikes lasted:

Mahatma Gandhi:Gandhi undertook numerous hunger strikes, ranging in time from days to several weeks.

Alice Paul: An American suffragette, Paul went on a 22-day hunger strike in 1917 while imprisoned at Virginia’s Occoquan Workhouse. She was eventually put in the psych ward and, according to reports, force-fed raw eggs.

Charles Robert McNabb: The convicted arsonist from Washington state lasted more than 100 days on water and coffee in 2004. Prison officials attempted to force-feed him despite McNabb’s efforts to maintain his fast. In 2008, a judge ruled that he did not have a constitutional right to starve himself, and he was force-fed.

Washington Post photographer Ricky Carioti contributed to this story.