Presenting their findings, which have yet to be peer-reviewed, experts from the Peninsula Medical School at the universities of Exeter and Plymouth said there is no evidence the drugs work.

In a separate study, German researchers also found no evidence that supplements aid weight loss.

The U.K. team reviewed existing data, including on guar gum, bitter orange, calcium, glucomannan (a dietary fiber), chitosan (listed as a fat absorber), chromium picolinate (sometimes sold as an appetite suppressant) and green tea.

Presenting their findings at the International Conference on Obesity in Stockholm, they wrote, "The findings from systematic reviews fail to provide sufficient evidence that any food supplement can be recommended for reducing body weight.

"A wide range of herbal and non-herbal food supplements is currently being promoted for weight loss.

"While mainstream drugs for body weight reduction must demonstrate efficacy before receiving a licence, food supplements do not need to meet this requirement.

"Few food supplements have therefore been submitted to clinical trials, and many healthcare professionals feel uncertain about their therapeutic value."

Meanwhile, experts at the University of Gottingen in Germany carried out an eight-week trial on nine common weight loss supplements bought over the counter.

These included cabbage powder, bean concentrate, some plant extracts and a fiber formulation.

A total of 189 overweight people were split into 10 groups, with some given the weight-loss supplements.

While those on the supplements did lose weight, they did not lose any more than people taking a fake pill.

The authors wrote, "All tested over-the-counter products for weight reduction showed no better efficacy than placebo."

Victoria Taylor, senior heart health dietician at the British Heart Foundation, said, "There are no quick fixes when it comes to weight loss.

"To reduce weight we need to be using up more energy than we are taking in, and to achieve this, we have to make changes to what we eat and how much activity we do.

"A huge amount of money is spent on the dieting industry, but it's often money down the drain.

"Small, sustainable changes to diet and physical activity are likely to be the most effective approach to keeping weight off in the long term -- and it needn't cost you a penny."

Nutritionist Carrie Ruxton said supplements could be beneficial when bought over the counter rather than online.

Referring to these "safe" options, she said, "They do little harm and may indeed motivate consumers to comply with diet and exercise regimes by inducing a small amount of initial weight loss."

However, she warned, "Supplements for weight management are no substitute for a calorie-controlled diet and exercise as a means of controlling weight.

"Weight management supplements vary widely in their efficacy. The European Food Safety Authority (EFSA) is currently assessing the evidence for a number of products and will announce, within the next few months, which ones will be able to continue making weight-loss claims."

She said the evidence for products such as green tea having a role in weight management was "stronger than for most other ingredients" but added, "There are too few randomized, controlled trials in humans."  

From the July 13, 2010, Prepared Foods' Daily News
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