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No miracle cures for weight loss |
With 63% of Australian men and 47% of women now overweight or obese it is not surprising to see the weight loss industry booming. We are bombarded with advertisements in the media and the shops are full of all sorts of supposed weight loss cures. Many of them make it sound so easy. The big question is do they work? Whilst we as GPs may be somewhat sceptical, some patients who may be quite vulnerable are often enticed to spend their hard earned dollars on measures that have no proven benefit, only to be let down when they don’t work.
A recent article published in the Medical Journal of Australia (1) reviewed the effectiveness of popular, non prescription weight loss supplements including brindleberry, capsaicin, caffeine/guarana, l-Carnitine, chitosan, chromium picolinate, Fucus vesiculosus, Ginkgo biloba, pectin, grapeseed extract, lecithin, horse chestnut, sweet clover/soy beans and St John’s wort. These substances are found in readily available and often highly promoted weight loss products trading under names such as Beer Belly Busters, Slim Life, Brindleslim, Body Lean, Chitosan, Fat Breaker, Fat Metaboliser, Cellasene, Fatsorb, Exofat, etc.
The review concluded there is no good evidence to support weight loss benefits from most of the substances reviewed. Even where there has been theoretical basis for a substance, no convincing data is available to provide evidence of efficacy. There is limited support for capsaicin, caffeine and fibre but only when they are consumed in foods and even so, the evidence is not strong. Only caffeine combined with ephedrine appears to be effective but side effects limit the usefulness of this combination. Possible synergistic effects of different ingredients cannot be dismissed, but cannot be assessed from existing data.
That is not to say research on these weight loss products may in the future show some benefits but until it does there should be some controls on the advertising that makes unverified claims. The weight loss industry is now coming under the eye of the Australian Competition and Consumer Commission and they have warned that companies will be prosecuted if they manipulate vulnerable customers. Consumer protection demands that weight loss claims should be based on evidence.
Of course, many of the above products are marketed in conjunction with a lifestyle program involving a low fat diet and increased exercise. This in some instances may produce good results but that is because of the program not the product. Lifestyle changes should be the basis of all weight loss initiatives, but there are of course limitations of effectiveness in the modern “obesogenic” environment where opportunities to be more physically active have been removed and energy dense food is so readily available.
Other misleading claims are made about some exercise machines. Recent television advertising has promoted products such as vibrating belts. The only exercise machines that work are the ones where one has to expend a lot of energy, particularly those that involve lifting the body’s own weight such as treadmills, stair climbers and mini-tramps.
Unfortunately people tend to look for a quick fix when it comes to losing weight and they are so vulnerable to misleading advertising. GPs are well placed to steer their patients away from wasting their time and money on such products. It is now helpful to have access to an up to date review article to give accurate information to our patients. The web site address for this review article is www.mja.com.au/public/issues/171_11_061299/egger/egger.html
(1) MJA 1999: 171: 604-608
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