The original Thanksgiving celebration was probably a 500-calorie meal that included small servings of venison, wild fowl and corn. It was eaten by men who were “chopping down wood with axes and hauling it home,” said Kathleen Wall, colonial foodways culinarian at Plimoth Plantation in Plymouth, Mass., a living museum of the 17th century. “These guys were not on the couch watching TV.”

Over the years, Thanksgiving has become a national binge, with overeating virtually a patriotic responsibility.

These days, bellying up to a bountiful meal, Wall said, is “so last century.” So much so that some Washington area residents say they are trying to opt out of the chow fest and downsize food’s role in the holiday.

For the first time, Julia Paik will spend Thanksgiving morning leading a 5K team to raise money for SOME (So Others Might Eat), an organization that serves the homeless and hungry in Washington. The teams have given themselves names such as “Huffin’ for the Stuffing.” Paik’s seven-member team is called “Shakin’ Jelly, for that Belly!”

“Health is part of it. Also, unemployment is at a record high,” said Paik, 32, who works at a social justice nongovernmental organization and lives in Rockville. “It just seemed like the right thing this year.”

The holiday invariably reflects the times. “Having to look at Thanksgiving over the last 400 years, I find that it’s always a barometer for the country. It’s a shape-shifting holiday,” said Wall. She noted that in the 1970s there was a counterculture movement against Thanksgiving because it seemed to ignore the killings of Native Americans that unfolded in the years after the friendly feast. Some Native American groups held “Days of Mourning” and “Un-Thanksgiving.”

On Thursday, yoga instructor Kimberly Wilson is planning a downward-facing-dog blitz at her Tranquil Space Yoga studios in Dupont Circle and Arlington County, adding more Thanksgiving classes by public demand, with the money going to charity — “so people can spend time in reflection.”

Wilson chose to celebrate Thanksgiving a week early at the Poplar Spring Animal Sanctuary in Poolesville, where rescued turkeys ate first. The birds dined on grapes and apples, while the people enjoyed a vegan potluck.

Part of the emotional tug of Thanksgiving gluttony comes from America’s creation myth: triumphing over scarcity to become the wealthiest nation on the planet. What could be more American than a holiday that celebrates our near-extinction with overindulgence, chuckled Brian Wansink, who served as executive director of the USDA’s Center for Nutrition Policy and Promotion under President George W. Bush from 2007 to 2009.

“It’s a very powerful part of our mythology. We were poor, then we were rich. It impacts us at the table,” said Wansink, author of the book “Mindless Eating: Why We Eat More Than We Think.”

As the title of Wansink’s book suggests, the bounty is now the bane. Skeptics say opting out of pumpkin pie and stuffing doesn’t sound like much fun. But Thanksgiving refuseniks fire back that what’s even less fun is a quadruple bypass, diabetes or, perhaps most common, finding that you can’t even fit into your fat pants, much less the skinny ones.

An estimated 63.1 percent of adults in the United States were overweight or obese in 2009, according to the Gallup-Healthways Well-Being Index. The survey finds that 36 percent of Americans are overweight and 26.5 percent are obese. Obesity rates tripled between 1980 and 2004. The rates have slowed since then, which could mean that Americans are cutting back, experts said.

“Thanksgiving is unusual because the standard items are fairly nutritious, and could be a lot worse. But people certainly pig out,” said Michael Jacobson, executive director of the Center for Science in the Public Interest, which publishes the Nutrition Action Healthletter.

To combat that tendency, Weight Watchers and other national weight-loss programs hold special sessions on cutting back and finding other ways to celebrate Thanksgiving.

Today’s Thanksgiving meals can balloon to more than 4,000 calories, depending on portion sizes and preparation methods, said Neal Barnard. He is featured in the documentary “Forks Over Knives,” which argues that Americans are endangering their health by eating too much meat.

“The problem is, in the old days having a feast was in contrast to the rest of the year — now every day is a feast,” said Barnard, an associate professor of medicine at the George Washington University School of Medicine.

During a Weight Watchers meeting last week at White Flint Plaza in Maryland, members were given paper plates and told to map out their holiday meals.

Many were shocked by calorie totals that represented as many as four days of meals.

“We can step back and think about [whether] the holiday is anything besides an eating frenzy,” said group leader Margaret Weiner.

Those at the meeting joked about how hard it would be to turn down a favorite aunt’s biscuits and gravy or pecan pie.

Wansink, who is also the director of Cornell’s Food and Brand Lab and known for his research on “portion distortion,” offered this advice:

“There’s nothing greater than being thankful to our host, even if the turkey is dry or the gravy is burned. So we shouldn’t whine about being on a diet and ruin everyone’s day,” he said. “Then again, use an old-fashioned plate! Maybe one from Europe. It’s smaller and people will eat less.”