"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.
"I'm pretty solid, actually. I'm not, like, 110 pounds," she told Elle. "But I'm probably heading towards that."
Liz Hurley: Eliminate Wine and Coffee, Add Vodka
Model-actress Liz Hurley, 44, also subscribes to the belief that alcohol can add unwanted pounds -- just not all alcohol. To keep her famously slender figure since having son Damian, now 7, she has eliminated wine from her diet but added vodka.
"No, I don't miss having a glass of wine because I've switched to vodka," she was quoted as saying in Britain's Daily Mail. "I don't really like vodka that much, but if I'm at a party, I have a small one with a lot of fizzy water and a huge squeeze of lime. Initially, it's like medicine, but I've got used to it now."
"I'm skeptical," Ayoob said. "Swapping out one alcohol for another is not likely to lead to weight loss."
Hurley has also cut coffee. "I used to drink an awful lot of coffee, but I was told after the age of 40, you have to be careful with coffee and wine. Apparently, that can be one of the reasons older women get bloated around their stomach."
Ayoob said coffee is virtually calorie-free and if anything, it acts more as a diuretic than to cause bloating. Alcohol, on the other hand, can cause bloating in the long run. Regardless, cutting both out will only result in a loss of water weight.
So what does Hurley eat? Soon after the birth of Damian, she revealed to the media that she only ate one meal a day and often went to bed hungry. And last year it was reported that she allows herself just one square of organic chocolate or one tablespoonful of ice cream when she wants a treat.
"Too many times celebrities want to drop weight fast and they don't care how they do it," Ayoob said. "But you want to spread out your calories. Otherwise, you're going to slow your metabolism."
Gwyneth Paltrow: Cleansing
"I need to lose a few pounds of holiday excess," she wrote. "Anyone else? I like to do fasts and detoxes a couple of times during the year, the most hardcore one being the Master Cleanse I did last spring. It was not what you would characterize as pretty. Or easy. It did work, however."
The master cleanse, which Beyoncé claimed helped her lose 20 pounds for her "Dream Girls" role, is a trendy liquid diet, also known as the maple syrup diet. Dieters drink a concoction of syrup, lemon juice, water and cayenne pepper.
Paltrow offered on her site a more moderate seven-day detox diet designed by Dr. Alejandro Junger, author of "Clean." It includes chicken, smoothies, fruit and soups and eliminates gluten, dairy, sugar and processed food.
She also offered advice on maintaining regularity.
"If your bowel movements get sluggish, you can accelerate things by drinking half a cup of castor oil or using a mild herbal laxative. Bowel elimination is paramount for correct detoxification," she wrote.
Ayoob is not a big fan of fasts or cleanses. "The calorie deficiency might not be harmful but it's not likely to be all that beneficial either," he said.
He'd prefer to see people eat whole fruits and vegetables rather than turn them into juice and leave behind the pulp and other nutrients. "Your gut is a juicer," he said.
Madonna: Macrobiotic Diet
Paltrow once maintained a macrobiotic diet like her good friend Madonna, a long-time macrobiotic follower.
Back in 2002, the pop star told Larry King her one indulgence was toast.
"That's why when I'm sneaking and I'm having a moment of decadence, I eat toast with strawberry jam," she said.
Processed bread is discouraged in the macrobiotic diet, which is considered more of an approach to eating than a diet. Dairy products and nightshade vegetables, like tomatoes and potatoes, are considered no-no's, while whole grains, such as brown rice and buckwheat pasta, mild seasonings and fish, preferably obtained locally, are recommended.
"Macrobiotic means big life and it means getting the most of life -- the most life out of your food," Madonna told King.
That means Madonna's average dinner consists of "fish, grains, some kind of grains, some kind of cooked vegetable, salad," she said. "Simple, but tasty."
Madonna also avoids eating out. "I don't really eat food in restaurants -- you can never be sure what's in it, can you?" she once said.
Ayoob is not thrilled with the macrobiotic diet, because he's opposed to "anything that gets rid of whole food groups," he said. "It's basically dairy-free and meat-free.
"Madonna can hire a chef and personal trainer to maintain her lifestyle," he added. "But most people don't live like that. Besides, it's not going to make us Madonna. It never will."
Padma Lakshmi: A 10-Point Moderate Approach
As host of the cable reality show "Top Chef," model and cookbook author Padma Lakshmi inevitably gains 10 to 15 pounds by the end of the season.
To lose the weight, she outlined her 10-point plan in the latest issue of Glamour magazine, the first being to be realistic and patient with weight loss. Lakshmi believes food should be pleasurable, so no cutting out all carbs or being too restrictive. She also believes in using lots of spices to season food.
Like Madonna, she recommends eating at home over going out, starting the day with breakfast and incorporating two snacks between meals. She also suggests cutting back on alcohol and going heavy on the vegetables. And when it comes to dessert, go for low-calorie, portion-controlled sweets. Most important, she says, exercise.
"That's very reasonable and much more realistic," said Ayoob. "It's not going to produce a 20-pound weight loss in one week, but 1 to 2 pounds a week. And you're going to lose weight without going insane."
He especially likes her advice on dessert portions and said if you're unsure what's in something, only take two or three bites of it. Most of all, incorporating physical activity in your life, even making it part of your fun, is crucial. Dancing, for instance, is a terrific activity.
"You can make that party work for you," he said.