Two papers presented at an international obesity conference yesterday have found that a range of the most popular weight loss supplements available on the market are no more effective than a placebo.
According to the author of one of the papers, the science backing a variety of weight loss supplements is lacking. “The market for these is huge, but unlike for regulated drugs, effectiveness does not have to be proven for these to be sold,” said Dr Thomas Ellrott, head of the Institute for Nutrition and Psychology at the University of Göttingen Medical School, Germany. “Few of these supplements have been submitted to clinical trials and the landscape of products is always changing, so we need to put them through rigorous scientific evaluation to determine whether they have any benefit,” he said.
However, the manufacturers of weight management dietary supplement products who were contacted by NutraIngredients.com still stressed the ‘robustness’ of the science backing the efficacy of their products. Placebo-controlled Weight Loss
Dr Ellrott’s study was a randomized, placebo controlled, partly blinded eight-week trial, where 189 overweight or obese individuals were given either a weight loss supplement in doses recommended by the manufacturers, or a placebo. The nine supplement products tested were purchased at pharmacies in Germany. Labelled active ingredients were: Polyglucosamide, cabbage powder, Konjak extract, sodiumalginate-complex, bean concentrate, selected plant extracts, L-Carnitine, fibre formulation and Guarana seed powder. First Systematic review of all scientific literature
The second study, led by Dr. Igho Onakpoya of Peninsula Medical School at the Universities of Exeter and Plymouth, UK, claims to be “the first systematic review of all existing systematic reviews of clinical trials on weight loss supplements.”
Literature searches were conducted in five electronic databases to identify all relevant articles on nine popular slimming supplements. These include: chromium picolinate, Ephedra, bitter orange, conjugated linoleic acid (CLA), calcium, guar gum,