The market is full of weight-loss supplements, among which are “fat magnets", fat melting agents, appetite inhibitors and preparations blocking carbohydrate absorption. They generally do not bring the expected results.
Dietary supplements advertised as slimming agents usually contain chromium, fibre, multivitamins, carnitine, chitosan or linoleic acid (CLA). In ads they are presented as miraculous products ensuring unfailing weight loss, although there is no research confirming their effectiveness.
How is that possible? Unlike drugs which are subject to legal regulations, the effectiveness of dietary supplements does not need to be scientifically proven to enable their marketing. Therefore, examples of persons who instantly overcame obesity presented in ads are often completely false. Manufacturers of such preparations are not willing to register them as drugs so as not be obligated to prove their effectiveness.
The weight-loss hype
There have been attempts to test some weight-loss preparations in independent establishments. Dr Thomas Ellrott, Head of the Institute for Nutrition and Psychology at the University of Göttingen Medical School, together with his team tested nine popular weight-loss supplements. Among them were those with L-carnitine, polyglucosamine, cabbage and guarana seed powder, bean extract, Garcinia Cambogia extract, sodium alginate and tablets with fibre, and also selected plant extracts.
“The results revealed no statistically significant difference in weight loss between any of the analysed products and placebo," Dr Ellrott assures.
Let us quote another study performed by Dr Igho Onakpoya from the Peninsula Medical School at the University of Exeter and Plymouth University in the United Kingdom. Dr Onakpoya carried out a meta-analysis of all the clinical trials of weight-loss dietary supplements. The analysis covered nine popular preparations containing chromium picolinate, ephedra extract, bitter orange, linoleic acid (CLA), calcium, guarana, glucomannan, and green tea.
“The study lead to the same conclusions – no evidence was found that any of the analysed dietary supplements is an effective method of losing weight," Onakpoya argued.
A drug with confirmed effectiveness
There is no proof that calcium supplementation facilitates weight loss. Dr Magdalena Białkowska from the Food and Nutrition Institute in Warsaw quotes a study in which for 2 years obese women were administered 1500 mg calcium daily; this, however, proved to have no effect on their body weight.
According to Dr Białkowska, on the Polish market there is only one weight-loss drug named Orlistat; it is available only on doctor’s prescription and its effectiveness has been confirmed by scientific studies. The drug limits the absorption of lipids in the gastrointestinal tract. Other drugs have been withdrawn from use due to alarming side effects.
According to Dr Białkowska, dietary supplements should be selected depending on particular cases, and if their use for weight-loss purposes is justified. Some of them are useful only as the supplementation of restrictive slimming diets, depriving the system from valuable nutritional elements. These include preparations containing fibre, as they facilitate weight loss by causing satiety and reducing blood glucose, cholesterol and triglycerides levels, and at the same time increase the system’s sensitivity to insulin.
Nevertheless, no weight loss supplements and preparations can replace a balanced diet and being physically active.