7 Wacky Celebrity Diets and Weight-Loss Tricks

Hollywood stars make a habit of turning to drastic, and often unhealthy, weight-loss plans and tactics.

When it's your job to look good, there's no telling what you'll do to get there. U.S. News, which publishes annual Best Diets rankings, has rounded up some of the wackiest celebrity diets and weight-loss tricks of recent years. Warning: Most of these don't reflect widely accepted guidelines for weight loss or a healthy lifestyle, and some are downright dangerous, even if they do provide fast results. Here are seven:

Watercress Soup Diet. Elizabeth Hurley's secret to dropping 10 pounds in seven days: a diet of watercress soup. "I drink at least six cups a day when I am eager to lose a few pounds," she told London's Daily Mail in 2007. "It's fat-less, low-calorie, full of vitamins and iron, and delicious enough to serve at a dinner party." Watercress soup typically consists of onions, light chicken stock, three large bunches of watercress, and salt and pepper. Such a restrictive diet, however, could open the door to nutrient deficiencies, a weakened immune system, and rebound weight gain.

The Facial Analysis Diet. Kate Winslet shed pregnancy weight with the Facial Analysis Diet, created by celebrity nutritionist Elizabeth Gibaud. The premise is that differently shaped faces need different diets, and that facial imperfections, such as forehead wrinkles or large pores, can signal dietary needs. Red or puffy cheeks, for example, are considered signs of dairy intolerance. And people with shiny noses are advised to avoid mangoes, chocolate, yeast-related products, red wine, and white flour, while sticking to apples, cucumbers, potatoes, and oats. A facial analyst will first examine skin for markings, color, and texture, and then create a customized plan that begins with a two-day detox. Most versions of the diet are low in calories, but claims in the book aren't backed by scientific research.

The "Bleak Diet." In 2007, Mariah Carey told reporters that she'd dropped two dress sizes by following a "bleak diet" built around fish and soup prepared very blandly—no oil or butter, for example. On the plus side, the diet emphasizes lean protein, which is a healthy choice. But neglecting flavor makes for a monotonous diet that will likely prove difficult to stick to over the long term.

Vinegar shots. Megan Fox and Fergie have admitted to taking shots of vinegar—typically three times a day, before each meal—in the name of weight loss. Advocates claim that vinegar flushes out fats in the colon, helping the body digest food while curbing cravings. But vinegar isn't a weight-loss panacea, experts say: There's no evidence it does anything but leave behind an unpleasant taste.

Grapefruit oil. Carmen Electra reportedly carries a vial of grapefruit oil around with her, sniffing it whenever hunger strikes. However, no research suggests that grapefruit oil has appetite-suppressing properties.

The "Air Diet." Madonna has been linked to the "air diet"—dubbed by the French magazine Grazia as the "it" way to lose weight in 2010. The idea is to go through the motions of eating without ever taking a bite. Followers put food on their plates, cut it, dig their fork into it, and hold it up to their mouths to savor the scent—never tasting it. What can they consume? Soup made from water and salt. Madonna helped popularize the plan in a 2010 Dolce and Gabbana ad campaign in which she and other stars were pictured holding food to their mouths but not eating it. (It's unclear whether she has actually tried the diet.) Medical experts don't condone such a restrictive, low-calorie diet.

Master Cleanse. Beyonce famously used Master Cleanse to drop about 20 pounds for her role in the 2006 film Dreamgirls. For at least 10 days, those on the plan give up solid foods in favor of fluids. On the menu: not-quite lemonade, water, and laxatives. That means four cups of salt water each morning, a cup of herbal laxative tea at night, and six to 12 glasses throughout the day of a "lemonade" made from fresh lemon or lime juice, maple syrup, cayenne pepper, and water. Continuously cycling on and off the diet could lead to nutrient deficiencies, long-term weight gain, a weakened immune system, and heart and kidney problems.