Two studies of a selection of popular slimming supplements have found no evidence they help patients lose weight beyond the placebo effect, the International Congress on Obesity at Stockholm heard this week.

However, a third study revealed at the conference found structured programmes of the kind provided by weight loss can be effective.
 
The first supplement study study tested popular supplements against placebo pills in a randomised controlled trial, including L-carnitine, polyglucosamine, cabbage powder, guarana seed powder, bean extract, konjac extract, fibre pills, sodium alginate formulations and selected plant extracts.
 
Weight loss was typically 1–2kg in subjects using the products, while the placebo group lost 1.2 on average. No statistically significant difference in weight loss was found for any of the products when compared with the placebo.
 
The second study carried out by researchers at the Peninsula Medical School systematically searched literature on a range of weight loss supplements. It found no evidence that any of the supplements studied provided an adequate treatment for reducing body weight.
 
The third study compared patients referred to Weight Watchers with a group who received GP-led care including leaflets about healthy eating and scheduled weighing. Subjects in the weight loss club study arm lost nearly 7kg on average compared with less than half that amount among the GP-led group.
 
For more information visit www.ico2010.org