In an era when trans-fat obsessives scrutinize every nutrition statistic, fantasizing about obesity—even immobility—is just a twist on a cultural norm. If anything, the feeder fantasy merely perverts the more popular ideal of waifish women snacking on sprouts. "Fat is so demonized in this society that it actually makes it attractive," says Don Kulick, a New York University anthropolgy professor and a co-editor of the anthology Fat: The Anthropology of an Obsession. "It's a taboo that is both rejected and desired."

Still, feederism is highly controversial among fat-acceptance activists. Both the National Association to Advance Fat Acceptance and the International Size Acceptance Association have come out against the fetish. "Our official stance is that each person should have control over their own body," says Russell Williams, the ISAA's vice president of activism. "One partner shouldn't be controlling another's size."

Predictably, feederism has found a home where all kinks flourish: online, where sites like MySpace, DimensionsMagazine.com, and FantasyFeeder.com entertain enthusiasts who daydream about stuffing their lovers with crullers. In a seeming parody of the pro-anorexia "thinspiration" movement, gainers and feedees swap message-board tips on how to keep the pounds on. They celebrate the term super size, made notorious by Morgan Spurlock's 2004 fast-food exposé, Super Size Me, in abbreviations like SSBBW (Super-Sized Big Beautiful Woman) and SSBHM (Super-Sized Big Handsome Man). They know all about the evils of fast food. That's why they eat it two, three, even four times a day.

Ryan (some names in this story have been partly withheld or changed) is a 20-year-old student from Batavia, New York, who says he discovered his proclivity as a child, when he found himself excited by the scene in Willy Wonka & the Chocolate Factory in which Violet Beauregarde balloons into a giant blueberry. Robbie, a 22-year-old student from Staten Island, posts photos of his expanding belly, replete with stretch marks, and keeps a MySpace blog about gaining. (He was up to 290 before a stomach flu last winter robbed him of 20 pounds. "My belly looks quite deflated," his blog reads. "Wish me luck on getting back into shape. Round shape, that is.") Brian, 25, a student and Web-support technician, has gained close to 100 pounds in the past year; he's now 315 but aims to weigh 500 or more. Rivera, for his part, has garnered a small following through belly-jiggle videos he's uploaded to YouTube.

One of feederism's most glamorous figures is Nicki Hammond, the "Gaining Goddess." Hammond, who's from London, Ontario, was struggling to accept her weight four years ago, when she was 180 pounds. But she became fascinated by BBWs and SSBBWs, and when she decided to emulate them, her husband became an encourager. "I liked the way I was looking, and I liked the way my husband was reacting," she says. Hammond founded GainingGoddess.com, where subscribers pay to watch her pose in lingerie and buy Meal Deals—food she eats on camera. She weighs 420 pounds. She wants to reach 600.