Featured Research

from universities, journals, and other organizations

No evidence that popular slimming supplements facilitate weight loss, new research finds

Date:
July 14, 2010
Source:
International Association for the Study of Obesity
Summary:
New research evaluating the effectiveness of a broad selection of popular slimming supplements sold in pharmacies and health food shops has found no evidence that any of them facilitate weight loss. Two studies have found they were no more effective than the fake supplements they were compared with.

New research evaluating the effectiveness of a broad selection of popular slimming supplements sold in pharmacies and health food shops has found no evidence that any of them facilitate weight loss beyond the placebo effect.

Two studies presented at the International Congress on Obesity in Stockholm, Sweden, have found they were no more effective than the fake supplements they were compared with.

"There are scores of slimming supplements out there claiming weight-loss effects through all sorts of mechanisms of action. We have so-called fat magnets, mobilizers and dissolvers, as well as appetite tamers, metabolism boosters, carb blockers and so on. 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 Gφttingen Medical School, Germany, who lead one of the studies. "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."

Ellrott's group tested nine popular supplements against placebo pills in a randomized controlled trial. The supplements tested included L-Carnitine, polyglucosamine, cabbage powder, guarana seed powder, bean extract, Konjac extract, fibre pills, sodium alginate formulations and selected plant extracts.

The researchers bought the supplements from German pharmacies, changed the packaging and product names to make them look neutral and rewrote the information leaflet inserts to eliminate the product name from the text. They then gave 189 obese or overweight middle-aged consumers packages of either fake pills or of one of the nine supplements, each week for eight weeks, in doses recommended by the manufacturers. Some of the products came with dietary advice, while others didn't, so the researchers provided exactly the same advice as that written in the relevant product leaflets.

Average weight loss was between 1 kg and 2 kg across seven of the products, depending on the supplement, and was 1.2 kg in the group getting the placebo pills. No statistically significant difference in weight loss was found for any of those products when compared with the placebo.

"Most previous studies have examined only one product. This is the first to include nine supplements with different proposed mechanisms of action and we found that not a single product was any more effective than placebo pills in producing weight loss over the two months of the study, regardless of how it claims to work," Ellrott said, adding that if there is an indication for the use of weight-loss drugs, consumers should opt for regulated obesity drugs with proven effects (prescription or over-the-counter) instead.

In a second study presented at the congress, Dr. Igho Onakpoya of Peninsula Medical School at the Universities of Exeter and Plymouth, UK, conducted the first systematic review of all existing systematic reviews of clinical trials on weight loss supplements. The analysis summarizes the state of evidence from reviews of studies involving nine popular slimming supplements, including chromium picolinate, Ephedra, bitter orange, conjugated linoleic acid (CLA), calcium, guar gum, glucomannan, chitosan and green tea.

"We found no evidence that any of these food supplements studied is an adequate treatment for reducing body weight," Onakpoya said. "Annual global sales of dietary supplements are well over $13 billion. In Western Europe, sales of weight-loss products, excluding prescription medications, topped £900 million ($1.4 billion) in 2009. The weight-loss industry in North America is worth over $50 billion and Americans spend over $1.6 billion a year on weight-loss supplements. People think these supplements are a short cut to weight loss and may spend huge sums of money on them, but they may end up disappointed, frustrated and depressed if their weight expectations are not met in the long term."

Onakpoya said some of the supplements included the study were reported to cause some adverse effects. However, more rigorous research is needed, he said, as only very few trials have been of long duration and the number of patients in most of the trials has been small -- factors which together limit the conclusions that can be drawn about the effectiveness and safety of such supplements.

Ellrott's study was funded by a German consumer issues magazine, while the study by Onakpoya and colleagues had no particular funding, but Onakpoya's position is funded by an unrestricted grant from GlaxoSmithkline, which makes the obesity drug orlistat.


Story Source:

The above story is based on materials provided by International Association for the Study of Obesity. Note: Materials may be edited for content and length.


Cite This Page:

International Association for the Study of Obesity. "No evidence that popular slimming supplements facilitate weight loss, new research finds." ScienceDaily. ScienceDaily, 14 July 2010. <www.sciencedaily.com/releases/2010/07/100712103445.htm>.
International Association for the Study of Obesity. (2010, July 14). No evidence that popular slimming supplements facilitate weight loss, new research finds. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2010/07/100712103445.htm
International Association for the Study of Obesity. "No evidence that popular slimming supplements facilitate weight loss, new research finds." ScienceDaily. www.sciencedaily.com/releases/2010/07/100712103445.htm (accessed July 30, 2014).

Share This




More Health & Medicine News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Generics Eat Into Pfizer's Sales

Generics Eat Into Pfizer's Sales

Reuters - Business Video Online (July 29, 2014) — Pfizer, the world's largest drug maker, cut full-year revenue forecasts because generics could cut into sales of its anti-arthritis drug, Celebrex. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Nigeria Ups Ebola Stakes on 1st Death

Nigeria Ups Ebola Stakes on 1st Death

Reuters - Business Video Online (July 29, 2014) — Nigerian authorities have shut and quarantined a Lagos hospital where a Liberian man died of the Ebola virus, the first recorded case of the highly-infectious disease in Africa's most populous economy. David Pollard reports Video provided by Reuters
Powered by NewsLook.com
Running 5 Minutes A Day Might Add Years To Your Life

Running 5 Minutes A Day Might Add Years To Your Life

Newsy (July 29, 2014) — According to a new study, just five minutes of running or jogging a day could add years to your life. Video provided by Newsy
Powered by NewsLook.com
Ebola Outbreak Poses Little Threat To U.S.: CDC

Ebola Outbreak Poses Little Threat To U.S.: CDC

Newsy (July 29, 2014) — The Ebola outbreak in West Africa poses little threat to Americans, according to officials with the Centers for Disease Control and Prevention. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins