According to a new study, the expensive supplements relating to diet assuring dramatic weight loss by entrapping fat, blocking carbs, or boosting metabolism work no better than placebo pills.

German Researchers conducted tests on nine such products against placebo pills and it is supposed to be one of the most extensive trials of weight loss supplements ever conducted. During the eight-week study, they found that the supplements were no more effective than the dummy pills for promoting weight loss. This study on obesity was presented in Stockholm at the International Congress.

The nine supplements include the active ingredients like L-carnitine, polyglucosamine, cabbage powder, guarana seed powder, bean extract, Konjac extract, fiber, sodium alginate, or selected plant extracts either alone or in combination. These ingredients have been marketed for promoting weight loss in numerous ways. Guarana seed, found in many of the weight loss supplements sold over the counter in the U.S., is said to be an appetite suppressant and energy booster. L-carnitine is said to promote muscle growth while burning fat. The polyglucosamine protein chitosan, derived from the shells of crabs, shrimp, and other shellfish, is also a popular ingredient in weight loss supplements and are generally marketed as dietary fat blockers.

Researcher Igho Onakpoya stated that on an average Europeans spend about $1.4 billion a year on unregulated weight loss supplements and Americans spend about $1.6 billion a year on these products. Onakpoya and colleagues from the universities of Exeter and Plymouth in the U.K. found minute evidence while reviewing the research on the dietary supplements found that any of the widely sold, unregulated products they tested promoted weight loss. Onakpoya tells WebMD that the only thing these supplements actually help people lose is their money.

The only tested supplements found to promote weight loss were those containing ingredients, such as ephedra, which was banned in the U.S. in 2004 following a series of heart-related deaths linked to products containing the stimulant.

Study researcher Thomas Ellrott and colleagues from Germany's University of Gottingen Medical School conducted a survey on 189 obese or overweight middle-aged where half took commercially available supplements and half took the dummy pills and the findings reveal that the supplements marketed for weight loss did not prove beneficial.