"They are idolized by the public," Keith Ayoob, a registered dietician and director of the nutrition clinic at the Albert Einstein College of Medicine in New York, told ABCNews.com. "We hang on every word they say, whether it's good or not."
Celebrities swear by everything from macrobiotic diets to eliminating alcohol to skipping food altogether to get the weight off.
Kate Moss, that icon of uber-waif fashion, recently made headlines when she was quoted on the fashion Web site, WWD.com, as saying one of her mottos was "nothing tastes as good as skinny feels."
The phrase is commonly seen on pro-anorexia Web sites encouraging girls not to eat. Weight Watchers has used a similar slogan: "Nothing tastes as good as being thin feels."
Model Katie Green, who has campaigned the fashion industry to stop the use of super-skinny "size zero" models, told The Sun newspaper Moss' comments were "shocking and irresponsible."
Storm, Moss' modeling agency, told The Associated Press her words had been misinterpreted.
"This was part of a longer answer Kate gave during a wider-ranging interview, which has unfortunately been taken out of context and completely misrepresented," the agency said in a statement. "For the record, Kate does not support this as a lifestyle choice."
"People look up to models, but they probably ought to look up to their doctor or get advice from a registered dietician," Ayoob said. "Models know how to look good but not necessarily be healthy.
"Weight management should be about health, not cosmetics," he added. "For most people, losing weight is not going to result in a Vogue cover."
Instead, Ayoob encourages regular people to be more reasonable and strive for losing even 10 percent of their current weight. He said they will definitely feel and see a difference.
So, before we succumb to the holiday temptations, ABCNews.com decided to look at five celebrity diets to see how valid they are. Should you try these at home?
Kate Hudson: Eliminate Alcohol
Actress Kate Hudson, 30, recently revealed a new muscled look in British Elle after dropping 20 pounds for an upcoming role as a terminally ill woman. She claims she lost the weight by eliminating alcohol from her diet.
"I love my glass of wine. I love tequila. To be in New York for two weeks and not have one beverage, I'm not sure I've ever done that!" Hudson told Elle in an exclusive interview for the December issue.
Ayoob was surprised that Hudson could lose that much weight just by cutting alcohol. "Alcohol was clearly making up a large part of her calories; otherwise, cutting it out wouldn't have made that much of a difference," he said.
Alcohol does have a lot of empty calories -- around 90 for a glass of wine, nearly 300 for a pina colada -- but it can also have some health benefits, such as antioxidants in red wine, Ayoob said. Most people, though, can normally fit one glass of wine a day into their diet without a problem, he said.
What Hudson's weight loss does show, Ayoob said, is that excess weight is caused by excess calories, and if you cut out the excess, you will most likely lose weight.
Keep in mind, though, that this alcohol-free diet is coming from a woman who hardly looked like she had 20 pounds to spare and hinted she still had a little way to go.