From the real skinny on water weight to the truth about your thyroid, here's what you need to know about all those crazy weight-loss claims. Drink coffee and get skinny. Wear magnetic jewelry and slim down. No doubt you¡¯ve seen these and other intriguing weight-loss claims. Are they true? Before you invest time and money testing them, find out what the experts have to say.

Fiber
Claim: Eat fiber snacks and flatten your belly in 24 hours. Fiber acts like a sponge in the stomach, soaking up liquids and whisking them out of the body to smooth your tummy.
Truth:  Eating enough fiber helps prevent constipation and reduces your risk of heart disease and other illnesses. "It can also help you lose weight in the long run, but it won't reduce your waistline in a day," says Susan B. Roberts, Ph.D., professor of nutrition at Tufts University. "You may even look bigger because fiber can bloat you."
Magnetic Earrings Claim: Wearing magnetic earrings reduces hunger and food cravings. These earrings act on an acupressure point in the earlobe to dull taste and increase production of hormones that regulate cravings. You can lose 10 percent of your weight in nine weeks.

Truth: "There is no evidence of a biological basis for magnetic earrings affecting weight loss," says Richard Cleland, assistant director of the Federal Trade Commission¡¯s Division of Advertising Practices. ¡°In ten years working in this area, I have not seen a study that suggested an efficacy. A few years ago jewelry was reviewed in a scientific workshop examining weight-loss claims. The experts could find no feasible reason to believe it works.¡±

Chromium Level
Claim: Increasing your chromium level can help you slim down. Chromium deficiency impairs the body' ability to digest carbohydrates and regulate blood-sugar levels. This can lead to weight gain, fatigue and other health problems. Ingesting more chromium revs metabolism, helping you burn fat.
Truth: Insulin helps regulate appetite, blood-sugar levels and fat production. Taking chromium, a common element found in many foods, may help improve insulin function in people with diabetes and glucose intolerance. "There is conflicting evidence,"says Robert Saper, M.D., M.P.H., director of Integrative Medicine at Boston University School of Medicine. "But there are no convincing findings that taking chromium leads to weight loss," says Dr. Saper, co-author of a 2004 review of research on various diet supplements.

Diet Soft Drinks
Claim: Drinking more diet soft drinks helps you lose weight. People who start drinking more diet r-sweetened ones. By replacing one with the other, they cut calories and shed pounds.

Truth: A review of data from Harvard University's Nurses' Health Study II found that women who increased consumption of diet soda over a four-year span gained less weight than those how much they drank, but they still gained. A review of data from the San Antonio Heart Study found that while drinking either diet or regular soft drinks correlated with weight gain, people who drank diet sodas were significantly more likely to gain. There are many possible reasons, says Sharon Fowler, M.P.H., who co-authored the review. It could be that diet-soda drinkers who gained weight had started gaining before the study began, switched to diet drinks to try to lose, but kept gaining for other reasons. Some people also drink diet sodas and then indulge in other ways. There's some evidence, though, that diet drinks may increase cravings and food intake. "We can neither confirm nor rule out that the diet drinks were actually causing people to gain," says Fowler, a faculty associate in clinical epidemiology at the University of Texas Health Science Center. "If they were, though, drinking as little as one diet drink a day may put a person at increased risk."