Sometimes reader reaction is "heated," O'Connell said. "But on occasion they write and say, 'It's great to see my size.' Shape is always a hot topic for women whether in fashion or in Hollywood. No matter what shape you find yourself in, it's always a lightning rod."
But cultural observers and psychologists say snide comments on the unbrushed photos of Smith in Hawaii reflect society's unwillingness to accept larger women.
"We live in a hypocritical society where the media tsks-tsks about stars with eating disorders, but then attacks someone plus-size as 'a whale,'" said Michael Musto, who writes a gossip and celebrity column for the Village Voice. "Whatever advances the plus-size has made are generally half-hearted and very transitory. "
Some stars like actress Kate Winslet, who championed the larger girl a decade ago in "Titanic," have now dieted away to more svelte figures. Even full-bodied "Cheers" actress Kirstie Ally went on a diet.
Only a few years ago, the fashion industry lambasted models like Kate Moss for looking anorexic, but today the runway still showcases skin and bones.
Indeed, 33-year-old French model Johanna Dray, like Smith, is beautiful but voluptuous.
"The fashion industry is still really snobby," Dray told the San Francisco Chronicle. "There are only a handful of designers who have used big women for their shows. It's still pretty closed."
In Europe, the industry has taken voluntary initiatives to bar super-thin girls. Madrid's major fashion show applies weight limits, and Milan requires models to carry medical certificates. Similar efforts are under way in London and in France to promote a healthier look.
But waiflike models still dominate the fashion magazines, and fat women are still objects of ridicule, according to Musto.
"Vogue put Jennifer Hudson on the cover and then went right back to promoting stick-figure type women," he said. "Sadly, females have it way worse than males. An Alec Baldwin who's let himself go a bit is still considered a serious leading man, but if, say, Sally Field had gained serious poundage, she'd be out of work.
"The term 'fat and beautiful' has become a complete myth when it comes to the media's reactions to anyone who unapologetically flaunts some real, fleshy curves," he said.
A few bloggers have even jumped to Smith's defense.
Women who blog on TooFatForFashion.com had positive things to say about Smith: "She is a marvelous style icon for full-figured women, as someone who is both genuinely plus, and shapely and beautiful. That combination is rarely seen in the media."
But America's obsession with weight goes well beyond magazine covers. The deification of the perfect body hurts ordinary women and especially children, said psychologists.
Jenn Berman, Hollywood psychologist and author of "The A to Z Guide to Raising Confident Kids," said the rise in eating disorders among children at "younger and younger ages" puts pressure on young women to be unnaturally thin. "Women come in all shapes and sizes," she said.
"Unfortunately, the quickest way to insult a woman is to call her fat, and lot of people are jealous of a woman married to a celebrity and make the assumption her life must be easy and they are quick to be critical," said Berman.
"Being overweight is still an area where it is considered somehow acceptable to discriminate and be cool," she said. "If you commented about the color of a person's skin or the ethnicity of someone, people would be outraged."