For Chelsea Clinton, a vegetarian, it was the decision to serve meat to the guests at her July 31 wedding. (Short ribs, specifically, though there were rumors of Angus steak.)

For some couples, that is a concession too far.

“If your family loves you and wants you to have that special day, I think they can go one meal and not eat meat,” said Cecilia Kinzie, a vegan and food consultant in Petaluma, Calif., who served no meat at her 2009 wedding.

“If you go to an Indian wedding, you don’t expect Italian food,” added Ms. Kinzie, who had already appeased her family by spending her savings on a hotel reception rather than the honeymoon she’d always dreamed of. “So why should this be any different?”

As it turns out, the most political decision of Ms. Clinton’s wedding was not whether to invite James Carville. By choosing to have meat, she reignited a sensitive wedding-season debate among ethical eaters and the people who love them: To serve, or not to serve?

The issue generated heat — though little consensus — among readers of the blog Serious Eats last week. “The idea that anyone would expect someone who was vegan to serve meat at their wedding seems absolutely crazy to me,” wrote one commenter.

Traditionally, many vegetarians have served meat at their weddings, out of deference to their guests, an aversion to endless cracks about “rabbit food,” or simply because there weren’t a lot of caterers specializing in vegetarian food who could handle a 200-person affair, particularly outside New York or California. (Today many mainstream caterers can handle vegetarian weddings, but you can expect to pay extra for the special treatment.)

As a generation that learned to eat from Alice Waters and “Fast Food Nation” comes to the altar, the vegetarians among them are often refusing to leave their ethics at the door, according to wedding professionals.

“This generation is much more health conscious,” said Bryan Rafanelli, the Boston wedding planner who worked with Ms. Clinton, “and there are just so many more brides who are vegetarian or vegans or have allergies or just eat healthier.” At Ms. Clinton’s wedding, he said, a color-coded map indicated each guest’s dietary restrictions, ensuring that no one was served something that he or she couldn’t (or wouldn’t) eat.

Not every bride can afford that kind of precision, so priorities must be set. Which decision a couple makes depends largely on their philosophy of weddings: Is it really all about you, or does the comfort of your guests come first?

Kathleen Mink, a social worker in San Francisco, said having a vegan menu at her wedding last year was “a no-brainer” because she and her husband are so opposed to animal products that they don’t even use honey. No flowers were harmed for their party, either: Ms. Mink made tiny blooms out of felt.

“The day was to celebrate us coming together and who we are, and our choices every day are vegan choices,” she said.

Not everyone sees it that way. Fernanda Capobianco, a vegan pastry chef from Rio de Janeiro, plans to marry fellow pastry chef François Payard on Long Island in October, and — despite her ethical qualms — meat will be served.

“We are inviting chefs like Eric Ripert and Daniel Boulud,” Ms. Capobianco said. “How can we invite chefs and then have no meat? They’ll think we’re crazy.”

It helps that her fiancé, who is famous for his work at Le Bernardin, Daniel and his own bakery, is not a vegetarian.

Some vegetarians see their weddings as a chance to prove to their families that they are eating more than tree bark and lettuce.

“I really want to make this an experience where my guests turn around and say, ‘That was awesome, I’m not hungry, I can’t believe it was all vegetarian,’ ” said Erica DeLorenzo, a business development executive in New York. After some lively discussions with her parents, she is planning a meat-free wedding for next summer.

It was a bit of a tussle. “My mom’s Jewish and my dad’s Italian,” she said. “Food is a big part of celebration.”

Ms. DeLorenzo is cognizant of the dampening effect that self-righteousness can have on a party. “It’s a teaching moment, not a preaching moment,” she said. “I’m not trying to change anyone’s mind. I’m just trying to share with people how we live and hope people enjoy it and learn something from it.”

But no matter how tasty or sophisticated the menu, some guests will probably construe the exclusion of meat as a political act — or a personal affront.

When Patrick Moore, a salesman from Attleboro, Mass., arrived at an old friend’s wedding in 1999 to discover nothing but vegetarian options, he made an excuse about leaving the gift in his car so he could visit a sandwich shop across the street.

I remember coming back carrying the bag of half-scarfed chicken Parmesan, only to be caught red-handed by the groom

The groom had a sense of humor about the incident, but it still bothers Mr. Moore.

“I know it’s your day, but it’s not all about you,” he said. “Why have a wedding if you’re going to be like that? Just print a bumper sticker.”