One-in-five women report using weight loss supplements in the previous year.
There are three herbal supplements that lead to weight loss without making other changes to diet and exercise, according to a global review of 19 years of research.
These are green tea, white kidney bean extract and ephedra.
Only white kidney bean extract, though, has an effect on its own, researchers found.
To have an effect, green tea and ephedra were given to people trying to lose weight in combined preparations.
Dr Nick Fuller, study co-author, said:
“The problem with supplements is that unlike pharmaceutical drugs, clinical evidence is not required before they are made available to the public in supermarkets or chemists.”
The research reviewed 54 randomised controlled trials including over 4,000 people.
Each compared various herbal medicines with a placebo control group.
People in the studies made no other changes to diet and exercise, other than taking the supplement.
While the results showed that green tea, white kidney bean extract and ephedra had an effect, the amount of weight loss, on average, is relatively low.
People in the studies lost less than five pounds compared to those taking a placebo.
Dr Fuller said:
“This finding suggests there is insufficient evidence to recommend any of these herbal medicines for the treatment of weight loss.
Furthermore, many studies had poor research methods or reporting and even though most supplements appear safe for short-term consumption, they are expensive and are not going to provide a weight loss that is clinically meaningful.”
Around 16 percent of people report that they have used a weight loss supplement in the last year: 12 percent of men and 19 percent of women.
Common herbal supplements for weight loss include African mango and garcinia cambogia.
However, despite being safe, many of them have little or no effect, as this study underlines.
Those that do have an effect are only linked to small amounts of weight loss.
Dr Fuller said:
“The growth in the industry and popularity of these products highlights the importance of conducting more robust studies on the effectiveness and safety of these supplements for weight loss.”
The study was published in the journal Diabetes, Obesity and Metabolism (Maunder et al., 2020).
